I've just booted the live ISO in VirtualBox, and the default desktop is clean, slick, and fast. I've got an Ubuntu 11.10 VM on this machine as well, which took much longer to boot and is all around less responsive. Linux Mint GNOME3 is a step in the right direction IMHO, my is still heavy to run on my four year old Dell XPS. Because GNOME3 uses the GPU directly, my poor old mobile series nvidia gets extremely hot and slow to respond when using GNOME3. I'm currently running ArchLinux+awesome on my laptop, but I might switch to Mint12 LXDE since I'd rather have something non-rolling release on my laptop since I never use it, and LXDE might be something nice to try.