They are supposed to be easier to upgrade because the barrel is easier to remove. also supposed to have a better trigger. But thats all a matter of opinion.
I dunno, I've never been much for guns. I mean, sure, we have the usual gun by the door, another near the TV, one in the kitchen, and another in the bedroom...and several others laying around. For the most part though, we keep our home free of guns. We are peace loving folks.