I have a Dreamspark account, so I have been running the same version you will buy in the stores for a few days now. It requires a bit of change to the way you think - took me a while to find the shutdown selection. (note, go to the lower or upper right side corner, a menu will appear, select settings, it is in there (control panel is in there too). I do like the tiles, once I got used to them. I added my most commonly used programs to the metro tiles page and removed all the stupid stuff I do not want. If I want something else, I just start typing and it comes up with suggestions. There is also a desktop tile - click it and you are back to your comfortable old desktop again.
Windows boots to the metro screen in 15 seconds - and this is with a normal 7200 rpm HDD. It took over a minute to do it with Win 7 on the exact same machine as a point of reference. I was shocked at how fast the metro screen appeared and something was wrong (it was a cold boot - I removed the 3 seconds of BIOS time from the startup since that is not anything MS can change).
Almost all my Win7 drivers worked without a need to change them - but I changed to Win8 drivers anyway. My Cisco VPN client stopped working and reinstalling it did not help. I now run the free Shrew Soft VPN Access Manager which can import Cisco profiles and connect without an issue. I had to remove Microsoft Security Essentials prior to the upgrade, but then Win8 put a new version on for me.
My only real complaint is how the new IE10 deals with flash - which is horrifying bad. It has a LOT of trouble with this forum as well - the drop downs do not appear unless I go to compatibility mode and back out of it again. Forum Nav drop down, mark forums read, etc. Forget about facebook games. I now use Firefox for facebook.
Everything is a bit peppier now that I am running Win8. I like it for my gaming machine. I am not sure if I will upgrade my HTPC or not since I am using old hardware (Intel E7200 CPU) and do not want to worry about potential driver problems.