All: I wasn't sure which forum would be appropriate for this question, so I hope this is the proper venue. I've trained with Sigs exclusively. I don't have an abundance of training. . .Probably 2-3 days of tactical shooting training at Sig Academy. I'm considering an HK45. My mental issue with this is the significant difference between these pistols in terms of magazine release. I had a USP Compact, and it was the best shooting gun I ever had, but I felt I needed to get rid of it b/c it screwed me up for every other gun I owned. When I went back to my Glocks or Sigs, the sights and trigger were very different, and all of a sudden, I couldn't shoot them for crap. Also, the mag release on the HK was impossible for me to use under stress b/c I'd never trained with it. The argument for the HK mag release is strong. I can definitely see the advantages of operating the release with the trigger finger. Also, as a Sig Armorer, I can see that Sig's quality is obviously in the toilet right now, and they are being dominated by marketing now, as opposed to engineering and quality. So I am inclined to think the HK's coming out right now are better built overall. My question is, can one use any other pistol along with an HK? My gut tells me if I train and carry the HK, I am no longer going to be able to carry a Sig b/c of the mag release. From what I have read, any time there is more than one way to accomplish the exact same task, there is at least one additional second required to make the decision which method to use. I am not sure I can reconcile the different operations under any kind of stress. This is the same reason I won't carry my EMP. The external safety is not something I have ever trained on. Are my concerns valid? I am curious what the experts say on this b/c although I shoot for fun, my primary concern when I purchase any firearm is utility for self-defense. Thanks for any thoughtful discussion or comments you can provide.