I've been sitting on a copy of Vista Business for a while, but although I had Vista RC1 installed to play with, I never really found anything that enticing apart from the fact that it looks a lot better than XP so I never made upgrading a priority. Had some time over the weekend, and I was upgrading a few other things as well anyway so I took the plunge and upgraded my Toshiba M200 tablet (using an external DVD drive).
Everything went very smoothly, but it took ages, and I actually mean ages. Vista's upgrading process itself took over 4 hours! After that I had to download and install all the additional drivers and stuff for my M200. I wish Toshiba would provide a single download and install process for all the drivers - would make the process a lot smoother.
Tip: remember to uninstall all your TOSHIBA (or other laptop specific) drivers before you upgrade to Vista, otherwise some of the crappy uninstall programs won't work.
First impressions - like the new look, and it seems more responsive, if not faster. And I can see why people like the search so much - it actually is very fast, efficient and easy-to-use, searching your programs, files and documents all inside the start menu. It does mean your HD spins more than usual because it needs to continually index your data, but it doesn't seem to degrade system performance. You can even adjust its intensity when you're on battery power. The tablet panel now peeks out from the left side of your screen (and cleverly hides when you call up the Start Menu so it doesn't cover it), and works pretty much as good as the XP one. The new pen flick feature is nice too.
All my laptop features work fine, including wireless LAN, Bluetooth, accelerometer and the tablet buttons (only the Fn key shortcuts, not the pen buttons on the side of the screen). Many of the Toshiba utilities have been vista-rised as well, and there are some new ones like the Windows Mobility Center tiles, which gives you quick access to laptop-specific functions. I think it's designed to replace the old CrossMenu which doesn't have a Vista version.

Tip: if you don't want to use the Toshiba Bluetooth stack (which I find is less efficient and more processor/memory-intensive), do not install the Toshiba Bluetooth Stack download. Just install the Toshiba Bluetooth Monitor download, and you'll see a 'Bluetooth Devices' option magically appear in your control panel. The Toshiba Bluetooth Stack however better supports devices, so if your Bluetooth devices don't work with the Windows one, try the Toshiba one - just install the Toshiba Bluetooth Stack download instead, not the Monitor download. The Bluetooth adapter is the 'unknown device' that Vista keeps asking for drivers when you first boot up, so install one of the options above to get rid of that.
All my apps work so far. I have also dumped Yahoo! Widgets in favour of the new Windows Sidebar, which seems a lot more efficient and less memory-hungry. Unfortunately, there's no TV Guide gadget available though (unlike the IceTV Yahoo! widget).
What I'm liking the most so far are the tiny changes that they've added into Windows Vista, like the new hints that pop-up when you drag and drop files, or the new 'you still have programs running' dialog that pops up when you restart/shutdown. These small touches make a product good as much as the big-title features I reckon.

As for UAC, I'm over the worst of it as I'm pretty much done configuring it, but it's just as annoying as the prompts you get on Linux and Macs, which are a bit more annoying as you have to enter in your password. On Linux and Macs however, you can do more before you have to enter in your password - for example, you can view your printer settings without entering in your password.
The most disappointing thing is that I can't use Aero Glass because the nVidia GeForce Go 5200 chip in the M200 is not powerful enough (only rates a 1.0 in the performance scores). You can switch it on, and it'll work, but when you open a few more apps, it'll switch back because of performance. The video driver from Toshiba is fairly old and because nVidia doesn't support laptops in their official ForceWare driver releases, there's no official way to update it.
The unofficial way is to hack around the limitation using the resources at a great website, laptopvideo2go.com. It's nothing difficult - just download the driver and the modded INF from their website, extract the driver to your desktop and replace the original INF file with the modded INF file. Then double-click setup.exe and you're away.
I'm currently using v100.65 because I've found it the most stable, especially for multiple display support (see this thread). Version 100.65 is available here.
Tip: if you want to use multiple monitors, remember to go to Control Panel -> Toshiba HWSetup -> Display tab and select "LCD + Analog RGB" then restart, otherwise you won't get any video on your second display even though Windows knows it's there. Things may seem funny when you reboot, but they usually work out after you log on. It is still a bit iffy sometimes and you can only have it in the primary-left, secondary-right position, otherwise funny things will happen when you resume from hibernation/sleep; definitely not as smooth as it was in XP. Maybe SP1 will fix this, or when nVidia delivers decent drivers.
I guess I don't have any excuse for not helping people with Vista problems now, damn it 
UPDATE (4/7/2007): I read a tip on the net that the Microsoft drivers for the nVidia cards were actually better at supporting multi-monitor setups than nVidia's drivers, so I tested it out - so far they're much more stable, and can handle setups not in a primary-left, secondary-right position without a problem (I have a primary-right, secondary-left setup). Not sure if it means no Aero Glass or games though, or if the performance is any worse - it doesn't seem to be, but I don't use Aero Glass (as the graphics chip isn't good enough) and don't play games on my laptop much anymore.
To force Windows to use the Microsoft drivers for nVidia cards instead of the nVidia ones, right-click on your desktop, and click on Personalisation. Then click Display Settings, then Advanced Settings. In the adapter tab, under Adapter Type, click Properties and allow the action. Then click on the Driver tab, and click the Update Driver button. Select the 'Browse my computer for driver software' option, then the 'Let me pick from a list of device drivers on my computer' option. When it finishes searching for drivers it'll come up with a list of drivers. Chances are the Microsoft drivers aren't there, as Vista prefers the nVidia ones, so untick the 'show compatible hardware' checkbox then select NVIDIA as the manufacturer. All the Microsoft drivers are listed at the top of the model list, and have a '(Microsoft Corporation - WDDM/XDDM)' ending. Find the Microsoft driver for your model - if there's a choice between XDDM and WDDM, choose WDDM (XDDM uses the legacy XP display platform which still exists in Vista; WDDM uses the Vista display platform). Click Next, complete the installation, click Yes to restart and multi-monitor setups should be much more stable on reboot.
UPDATE (5/7/2007): Went to MODM 3 last night (great night), and while talking to Michael Kordahi from Microsoft about UAC, we thought - wouldn't it be good if UAC worked like firewalls do now, so you can permanently authorise certain applications launched in a certain manner (e.g. by user by double-clicking desktop shortcut) until the application's executable/library changes, in which case a new confirmation would be needed. So if I permanently authorise Device Manager when launched from the Control Panel, then the next time I launch it in that manner, I won't get a UAC prompt. However, if another app wants to launch Device Manager I would be prompted to prevent the other app doing unwanted things through Device Manager without my authorisation. Likewise, if Device Manager was updated or hijacked, causing the executable/library to be changed, the next time I load Device Manager I would be prompted by UAC and again given the option to permanently authorise it once more. I'm sure this probably isn't a new idea, but one that should be given more thought.
UPDATE (8/7/2007): As you can see, I'm still fiddling with my Vista setup. I realised today that the Microsoft nVidia drivers I recommended in UPDATE (4/7/2007) actually don't work with the Toshiba Rotation Utility, so when you flip your screen around on the M200, the pen surface changes, but the screen orientation doesn't, so not only is it not in portrait mode, but your pen cursor os out of whack. I've now gone back to the nVidia drivers, using 97.59 as recommended here. On occasion, these drivers do not restore the screen display when resuming from sleep/hibernation, so to fix that, just press Fn+F6 or Fn+F7 (i.e. change the screen brightness) or plug/unplug the power to wake the display up, see here.
I've also discovered the point of the Toshiba Flash Card utility, installed as part of the Value Added Package download. Not named very well, but it actually is the software behind the Fn key shortcuts on your keyboard, so install it and make sure it's enabled by going to Start -> All Programs -> TOSHIBA -> Utilities -> Settings for Flash Cards, and unticking the Disable the Flash Cards option if it's ticked. It's called Flash Cards because the shortcuts can also be accessed by mouse (enabled by default in the settings dialog) - just move your cursor to the top (or bottom if you changed the default setting) of your screen, wait and the 'flash cards' will appear (see the screenshot below). Click on them and you can see further options, allowing you to change brightness, mute etc. Very slick animations I must add - nearly looks Apple-esque.

One disappointing thing though is that the pen buttons at the side of the screen don't work, and I haven't found anything to make it work, yet
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