unoriginal1 :
There's nothing wrong with 8. It's not a bad OS. I still prefer to use 7, just my opinion.
Basically just comes down to your thoughts and what you like the best. Have you had a chance to check 8 out? IF not go to your local best buy or something and navigate around on one and see how you like it.
As far as gaming differences the fps diff will be very minimal. Nothing you'll notice outside of bragging rights of a few fps here and there.
Yes and to further this, it is a few frames either side I've found. Some games run better on 7, others on 8. Internet browsing is also faster, as long as you internet speed can keep up.
It might take a while to get used to the Win 8 layout, but it is mostly the same. I heard that you can get the start menu back (or win 8.1 has that back or something), but you can use the Metro GUI just like it's a start menu anyway. (Remove things you don't want, put things you do want in place instead.)
It does boot somewhat faster, although having an SSD helps considerably in that area.
Important to note though: Unlike choosing hardware, choice being mainly based on performance and cost, less on looks and user interface, people's opinions can help choose things like OS, (which is often more towards looks and interface as performance often differs less than hardware upgrades), but the opinion that matters the most, is yours. The performance increase may not be that much more (and in some cases decrease) but you should test it to see if you like the way it functions, looks and if it works for you.