W8 seems to use about 300 MB less than W7, which is significant.
Boot is much faster, it's quite simply an improved OS under the hood.
I've been getting more network disconnects than normal ; and my games have been hanging/blackscreening occasionally ; though I installed some hacked Catalyst W8 driver (RC version) yesterday, which seems to have provided an improvement.
As expected, playing DVDs is as bad as in any other Windows pre-release version
W7 is VERY MUCH the backup system now