You have a driver issue or bad install, or a bug as you called it. It's not Windows 7.
Are you using an actual release from MS?
Windows 7 boots for me from the time I push the Start button on the front of the PC to the Desk Top = 29 seconds. Programs open up in Windows way faster than Vista.
One of the problems with upgrading from Vista instead of installing fresh is that all of the new files installed by Win 7 are going to be slotted into the bits and pieces of free space scattered all over your disk. This means they're very unlikely to be in the sectors that are fastest to access, and the head is going to have to move back and forth a lot more when you boot and have to read all those pieces from the drive.
The freezes I can't speak for, but my guess is that the slowness is probably a result of the upgrade.
The official MS upgrade version isnt out yet, right? So you upgraded to a RC with a work around. Am I right?
For your final Windows7 install do yourself a favor and do a fresh install. Save all your files to a remote HDD and transfer after the fresh install is complete.
And what version of W7 are you installing?
You want a free for 90 day official release version of W7 so you can get the real feel? http://technet.microsoft.com/en-us/evalcenter/cc442495....
Oct 22 is the Official releas of Windows7 to the public.
Although i doubt this is it, i have seen high end rigs with vista upgrade to windows 7 and have noticed in some areas it being slower then vista - i take it windows 7 caches less and uses less available resources and ends up being slower because of that, especially on systems with ample resources (i7, 12gb, RAID0 etc).
Cant prove it but thats my guess.
As for the "upgrade" - thats the first thing NOT to do, format the system and download all new fresh drivers for the system (via windows update or directly from the manafacturer eg Realtek for Realtek Audio, dont goto the motherboard manafacturers etc) - see how that goes.