There seems to be a whole lot of hearsay and misconceptions about Windows 8. Some posts I have read on the first and second page simply isn't true or only half true.
I will give an honest(trying to keep it short) review of my experience so far to help those on the fence.
I installed the preview version on my Dell XPS 17 L702x laptop a week ago. It's a decent laptop with a 60gb SSD, i7 and 8gb Ram. Firstly install was done by downloading the ISO and a small microsoft app called "Windows 7 USB DVD Download Tool"
I then made a bootable USB3 drive (4GB is enough) and did a clean install which took about 10min.
I only had trouble with the card reader driver which would not install but got it working by manually updating the driver with device manager.
Boot speed is phenomenal! I almost could not believe it, between 7-9 seconds to the log on screen and it's instantly accessible. I specially like that I could log in with my hotmail/outlook account and create a 4 digit pin for faster log in. From what I understand your desktop will be available from any trusted PC by logging in with your hotmail/outlook details, but I have not tested this. Skydrive is quite nice and by far the cheapest cloud storage I could find beating other big names by a factor of 10 on price! I have uploaded ~40gb which took a while(some 100-150KB/s) but encountered no errors.
Now I know most ppl hate change and it will take getting use to but so far I like the interface and the addition of apps. Everything feels smooth with just the right amount of bounce. Apps seem to work ok but I suspect they will get a whole lot better in the coming months. I spend most of my time in desktop mode and got use to the new program locations quite fast.
Got 2 or 3 screens? Maybe even more? You will love Windows 8. They completely redesigned the way multi screen set-ups work with many improvements.
I played GW2 and could not say if it was any faster or slower, it felt smooth and I had no issues. A quick search reveals initial benchmarks to show the same or marginally faster gaming performance. I expect this will get better as drivers are optimized.
There are some glitches also. Some of my laptop media keys sometimes don't function as intended but its not a big deal and I'm sure it will be fixed soon.
In the end I like the big changes, I think Microsoft HAD to take a big gamble and be bold, because they were falling behind and Windows 7 feels dated compared to what mobiles and tablets can do these days. I like the way they are trying to integrate everything across platforms and this is the reason I might very well buy a Windows 8 phone.
Make no mistake...Windows 8 is a BIG change in the code and looks, the biggest change since Dos-->Win95.
Like it or hate it...my personal view is that it's a really good start and I'm exited to see what they do next. I predict apps will take off(upset software companies aside) simply because many people who are not technically inclined understand apps easier than install instructions. Another plus for developers is that any app written for Windows 8 will run on mobile devices and desktops alike. The only possible problem I see here is the prices for Windows 8 tablets...we will have to wait and see.
Keep Windows 7 or upgrade, that is ultimately your choice. Me? I'm upgrading all 4 pc's in the house!
Hope this helps someone!