In my main rig I have dual boot 7 & 8.1. They are very similar, but 8 seems to run quicker and smoother. I use classic shell and have. A few shortcuts to some metro apps, but for the most part just use 8.1 with a standard desktop.
The trouble with new windows os is that microsoft only makes them and sells them to generate revenue, seems to me you should make the new one way better then the old one and then everyone would want to buy the new one and not have it forced on them.
Win 7 works fine for me, but I might buy one more slightly used copy of 8 to install on one of my secondary machines.