I've got them on all my bikes. I really like them - previously I had the spesh bg grips, but they would rotate and the ergons are lock on. I do find them a tiny bit small in diameter though as I have big hands.
Yeah, I have GC2s (see pic below) on my Dahon. If you get aching hands/wrists when riding, they'll do wonders. If you don't, not sure you'll be wowed. I'd get another pair for my bakfiets, but I wouldn't bother with any on my Kona