I switched about a month-6 weeks ago. Didn't think much of it until this weekend when I had the occassion to use a Tiger machine again. Leo just looks a lot cleaner to me now. Subtle, but worth it IMO.
I'd seriously wait if it works then don't go screwing around leopard still has issues wait till 10.5.4 Maybe then revisit the situation I wish I had tiger right now, It's not worth the risk.