Added a second 7200.11 HDD, and Dual Boot installed on the same machine as Vista 64.
Did a clean install from the Technet file (i.e. No Vista at all - even unplugged the original HDD).
The good: Easily the simplest install I've done. Start the computer with the disc in the drive, go make a cup of coffee, come back and answer the questions, and go watch TV. I come back, it's done and working. Maybe a half an hour, total, from blank start to booted Win 7. Reach out, grab the Media Player Patch, Win 7 drivers from ATI, and Vista drivers for my Auzentech Prelude. The chipset drivers from DFI wouldn't install - They 'detected an unsupported OS' and aborted. So I reached out to Intel, grabbed the standard P35 driver set, and pointed the Device Manager at the folder... Done deal. All detected, all reported as working. Job done.
I like the UI, though whoever chose the defaults probably mis~clicked... I like the much improved troubleshooting tools. It's clearly snappier than Vista in general usage. And my totally un-scientific testing says it's equal to better than Vista while gaming.
Haven't found any real 'cons', except it's demonstrating to me it's Beta status by randomly locking and forcing a hard reset. Not often - Once or maybe twice a day. Vista doesn't do that, and it's the exact same hardware. The troubleshooting tools don't show anything, except the restart error. A blue screen would be preferable, TBH, cos then I'd have something to work with. At this point, I suspect an issue between the generic intel drivers and my DFI mobo, though, rather than something with 7.