[pge]

Gnome 3 is great...if you have compatible graphics processing.

Ubuntu (and Gnome for that matter) are facing an interesting challenge there. Do you try to take Windows head on and assume your target customer is running new hardware? or do you try to keep the installed base of Linux users happy? Many of those are using Linux on older hardware precisely because it's still pretty snappy on those machines, while Windows is too bloated. It seems hard to have it both ways.

[bad_user]

You got it backwards -- newer hardware is the problem ;)

[rbanffy]

Gnome shell mandates compositing.

[owaislone]

Unity doesn't because it has a fallback shell that mimics actual unity 100%.