First post here... Great forum guys/girls ! I've been reading it for weeks.
I also have small hands. I really thought the smaller grip would help me but after a few hours of play I had blisters and my forehand was MAYBE inconsistent (more then usual). I went back to my 4 3/8, which is a bit big for my hand, and loved it alot more then the smaller grip.
I find it also a bit like golfing... I've played alot of golf (maybe some here can agree with this) and the smaller grips enables your wrist to move more then the bigger grips. I'm still new in Tennis, maybe I'm wrong, but the thicker grips keeps my wrist more calm when I stroke the ball. I guess it all comes down to preference.