I got my copy of Windows 7 Home Premium (full install license) from Amazon on release day, via pre-order. Â I wasn’t in a big hurry to upgrade since I’m already running the release candidate, which worked well since the last week has been pretty busy with family stuff (vacation, son’s first birthday). Â Even though I wasn’t in a huge hurry, I didn’t want to wait too long, so when my evening freed up last night I decided it was time. Â I didn’t technically upgrade, since I was already using the release candidate.
To start the process, I made a backup of my AppData and other user folders, then repartitioned and reformatted the drive. Â The complete installation time from booting the PC with the DVD in the drive until the desktop came up was 25 minutes. Â That of course was the easy part. Â The next step was about 160 MB of downloads from Windows Update for security patches and driver updates for my keyboard, mouse, monitor, and graphics card. Â This took about 20 minutes and required a reboot.
The only problem I had with Windows Update was the Nvidia drivers it installed.  It used the 191.07 Nvidia drivers which I found caused a stutter problem in Champions Online, but I was able to install the 190.62 drivers over the top of the existing 191.07 without any problems.
Installing software and games took another 5 hours, but I’m now back up and running on the Home Premium retail version. Â I did backup my MMO program folders. Â Instead of restoring them, I did re-run the installers but then I brought over the patched files before running the patcher. Â This way I get the icons in the Games folder setup correctly but didn’t have to sit through hours of patch downloads.
The only major pain I had was fixing the 30 odd podcasts subscriptions I had in my Zune software. Â There really should be a way to export those subscriptions as an XML to make it easier to move machines.
Since I was already on the release candidate, the upgrade really didn’t change much for me, but I’m still really enjoying the UI changes from XP to 7. Â It may not be worth upgrading an existing machine, but if you’re building or buying a new box 7’s definitely the way to go.
On the 32- or 64-bit question, I recommend 64-bit.  You may have some compatibility issues on old peripherals, but most components should be fine and I’ve not had any software issues except for UAC.