I'm a keyboardist, most of the metal stuff I've learned has been through guitar pro or by ear. The only bands that seem to ever transcribe their keys parts are is Dream Theatre, which is understandable seeing as how Jordon Rudess is basically "the guy" when it comes to anything keyboards. I've never checked out his site though, I wonder why. It never occured to me.
I'd really be interested in learning keys parts for bands like Shadow Gallery and Time Requiem, but I'm having trouble finding anything on them.