Well, I revamped my test system. Went to a newer Intel D865GLC mainboard, which added dual-channel support, and an AGP slot, among other things. So my testbed (the box formerly known as eMachines) now looks like this:
Intel P4 2.8GHz Northwood, 533MHz FSB
768MB DDR in dual-channel mode
120GB Seagate 7200.7 HDD
ATI All-In-Wonder 9700 Pro 128MB
DVD-ROM and CDRW drives
I took out the SoundBlaster Live!, since Windows won't be supporting Directsound3D (at least not in hardware accelerated mode any more). Then I obtained Windows Vista RC2 (build 5744) and installed from scratch. I had to install the ATI drivers later, but this went smoothly, and the beta drivers from ATI's site (I didn't install Catalyst Control Center) work well for what I've been doing. Due to a Microsoft bug, I had to do a minor registry edit to allow Aero Glass to be turned on (I hear this is a problem limited to RC2 only). I'm getting a performance rating of 3.9, which would be higher, but Vista's score reflects the lowest score generated by the MS performance analyzer, and my RAM and CPU had the lowest scores (graphics and HDD were far higher).
I've added the current Avast! Antivirus, Office 2007 Beta 2 technical refresh, Firefox 2.0 RC2, and Acrobat Reader 7.0.8. I've also set up my GMail account to run within the new Windows Mail application (I'm testing Windows more than I'm testing Office, so I didn't set up Outlook, though I will later).
So far, things run quite well. I think Microsoft's addition of the Junk E-Mail option added to their mail app will take some marketshare back from Thunderbird, which I've been using and like, but which doesn't seem to handle large folders full of mail as well as Microsoft has. I have had one reboot crash when I was doing a lot of stuff at once, but admittedly I'm running the system on an Antec 300w PSU that is probably working hard; it could also be that the two 128MB DDR modules are a little finicky. I'll make more notes as I go along; if anyone wants me to look into certain settings or options, just ask. At this point though, it's worth trying if you can get ahold of a copy and have a spare box; OS speed and stability are about where things need to be to run Vista full-time.
Intel Q9450 @3.2GHz, Gigabyte GA EP45-UD3P, 4 x 2GB G.Skill @4-4-4-12
Antec P160SW case (modded), Xigmatek 750w PSU
3x 500GB (RAID-5), , OptiArc 7200S, ASUS E818A3T
Creative X-Fi XtremeGamer, Hauppauge HVR-1800, Radeon 4890