I'm carrying MagSafe +P. I think it's in 62gr. but it is fragmented with the force of a slightly weak 45ACP. There is an article out there somewhere that is saying that MagSafe is very unreliable but I'l use it for the Summer. When winter hits I may go back to either the CorBon or the Hydrashok loads.
I carry no spare magazine for two reasons, a.) it's just more weight and something that needs to be hidden, and b.) I'm relying on statistics that say that the average gun fight will be over in less than 10 seconds and require only 0 to 3 rounds to be fired. I don't remember where I got those stats from.