It is true that the .40 has more of a snap and the .45 is a pusher. That is one of the reasons I like the .45. It is also the caliber I shoot more accurately with. If I were you I would not worry about it. Some like the .40 more because of the snap. It will recoil faster and get your sites back on target. I have never had a chance to shoot the .40 in an HK but I would assume it handles the round better than most. Worst .40 I have ever shot was a Glock 22. It had noticeably more recoil then my .45s. I am sure you will be happy with whatever you choose! There is no perfect round. Just be sure to practice!