I've been in the 'beta' since day one. I have it on my spare older "for class" laptop that I have for working on Visual Studio when at school. So it doesn't get a TON of use. The laptop isnt great, Core Dou 2.4Ghz 4GB ram, Geforce 130M (that overheats if I put games at it). I actually like it better than Windows 8 by a large margin as its pretty much Win 8.1 + 7 if they had a baby.
I dont have a ton of experience on Windows 8, mainly I only used it for NSCOM 220 'Client-side OS's' which was a way of saying "this is an overpriced class on Windows 8(.1)". (This class cost me more in books than all of my classes for my first year. Testout Code + MOAC code + MOAC book, of which is still sitting on my desk never opened. I love that Cisco has all their 'books' online for free if your a Netacad student) But I was able to get my OS MTA from it so I have that going for me. I'll probably still stay with W8.1 for my tablet though as the UI is pretty much made for touch.
Multiple desktops feature is nice, not a fan of the search being a permanent fixture on the task bar. Spartan browser isnt being tested atm (IIRC), so I know nothing about taht. There is still a few features I wish they would have pulled into it from 8, mainly the charms bar on the right. For no other reason then it was easy to find the basic settings of almost any program quickly.
Finding your way around via start menu is still a bit jankee, not as bad as 8, but just a little off if your used to 7. Probably more my fault then the systems since I havent put much time if any really into customizing. I'm just really happy they left the left click start to access practically every management tool feature.