2.2 is out. Still free, some new features that make it more streamlined for windows platform. Like directories for opening/saving files are much easier to use. Check it
yeah I've noticed even when I'm on a Live distro and doing some Gimp editing it applies effects n' stuff faster and all that junk. I don't know technical terms
Probably because Linux is a multithreaded environment, and it uses memory better than Windows. In other words, actually uses RAM instead of just swapping to the HDD.