I've got 10 running on some old hardware, ie, Asus P5Q Pro with a 3.16GBz Xeon Quad and 8GB of ram and it seems to be OK except for a missing driver for my 3D video card. I doubt seriously if ATI is going to update drivers for this Radeon 1650 in 10. I wanted to see if Unreal Tournament would run on it but without 3D drivers it's a "no go".
The addition of the start menu is a step in the right direction and begs the question of why they didn't do that with 8? I guess the fact that their sales of 8 were off 66% in the first year told them in a language they could understand, ie, money lost!
Ennywho, this Enterprise Preview version has all kinds of crap that is feeding info back to M$ built in that you CANNOT disable so be advised that whatever you have on your computer is subject to them seeing it. They even have it so you can't turn off the automatic update feature also.
The preview is good until April 15th, 2015 so I'll keep it loaded on this spare drive so I can play with it some.