I own a 43 and love it. That being said I shot a buddies shield, and the thought occurred that I wouldn't mind having one of those too. I think they both shoot like a bigger gun, yet carry like a sub-compact. My recommendation would be to find a range that rents both and try them out. They are similar sized, but they do feel different in the hand IMO. Renting the 43 and shooting it was what sold me on it. As far as capacity, I put a Pearce +1 on the mag I carry in the gun, and a ghost +2 on my backup mag. The ghost just adds a little too much length to the grip affecting the concealability to use it all the time.