Less stuff on screen, more steps = slow.
It is strange how nobody sane says "hey this Windows 8 GUI is better!" it's all "It's just as good as 7". Then why bother at all?
You referred to the 'old' being Desktop, which is just as snappy if not snappier than Win7's Desktop. Don't twist...
If moving your mouse a little more is that much of a productivity loss, increase your DPI/speed settings. If you cannot click giant squares because they are not smaller squares, seek a psychiatrist because it's a learning/adaption issue, possibly OCD.
I've seen improvements in 8 over 7. Easily enough to spend $40 and $15 (my new laptop qualifies and no it's not touch screen all over the place) The Desktop (where I've stated many times is where I mostly live) has improvements I like, the Start Screen I actually MISS now that I'm back on Win7 with my new laptop waiting for the official release of Win8 because of the updates the tiles provide and the Metro apps...meh. Some are fine, others are not. I'm sure they will get better/more of them in time.