I took the leap yesterday and installed Vista (5472) and Office 12 (4228) on my main machine (a Toshiba Tecra M4 Tablet).  Although it's still been less than 24 hours, I've been very impressed so far.  Both builds seem very stable and already I'm seeing some gains over my old setup.

My initial impressions:

Installaton - I used WDS (Windows Deployment Services) to install the build, which worked really well (although a rogue Thinkpad driver crept into the build and needed to be disabled shortly after installation).  Windows Update in 5472 is good, although a little "hidden" for my liking.  It took me a couple of minutes to dig through the control panel to find it in order to get the drivers for my machine.

Display - The Tecra M4 comes with an NVidia 6200 graphics card (128M) – after finding the right driver online, the machine now has a 3.0 performance rating, and Aero glass works really well.

Gadgets - I'll admit, I was a little skeptical when I first heard about Gadgets in Vista, but I think they are going to be cool.  I'm not one for displaying clocks, slideshows, or other such things on my desktop, so I quickly turned off the default selection - but I think custom-built, RSS "powered" gadgets will be very useful (and popular) once they start to appear.  My favorite out of the default set today is the CPU load gadget.  Much more entertaining than keeping taskmgr minimized in the system tray.

Tablet - I still need to work out the automatic rotate feature on the Tecra.  Screen orientation is supported in this build, but detection of "going into tablet mode" looks to be a feature of the Toshiba driver set that isn't there yet.  I believe there is a tool called iRotate that may provide this functionality until Toshiba release a new driver set.

Performance - I've been pleasantly surprised that the performance of this build is actually better than my old Windows XP setup.  Ok, my old XP setup was in desperate need of a rebuild, but even so...   Standby and Hibernate seem to be working well in 5472 on the Tecra - although I did see one glitch this morning (I think it had to do with a 2nd hard disk I was trying to plug in at the same time).

Security - When I played around with an earlier build of Vista (on a VPC) I thought I would get annoyed at the constant "do you want to allow this?" dialog boxes as part of Vista LUA.  Having gone through many of these while installing stuff yesterday (even logged in as admin on the machine), they require extra time, but after a while I found myself left with a good feeling that I'd quickly know if something rogue was being installed.  In a strange way, I'm actually becoming a fan of this feature...

Breadcrumb Navigation - Many explorer windows now support a "breadcrumb" navigation where you can quick navigate using "breadcrumbs", but then select all the breadcrumbs and copy the physical path - very cool.

Launching Programs - On XP, I used to run (and love) SlickRun to launch programs.  The Start Menu has a way of quickly searching for things, but I don't know whether it's possible to customize it with a set of shortcuts (which I really need) – it looks like I may be able to use “pinned” menus on the start menu providing I can make them work with parameters.

Handwriting Support - Really works well - much better than XP from what I've seen.

Other Apps - I've still lots to install, but no incompatibilities yet.  Foldershare is working well (and currently updating my libraries as I write this).

That's it for now - as I said, just the first impressions after a few hours of use.  I'm sure I'll have more to say as I start loading all my applications...

*** Updated video driver section - found updated driver (see comments) ***