I don't have a vp9B but I can tell you as a lefty all my non Hk pistols have button releases and I have never changed the mag release to the right side of the gun. I have many, many times shot a match on Thursday with a button mag gun then shot a Sunday match with an Hk and vice versa. I have shot with SIG's for several months then gone right to Hk and vice versa and I have never tried to hit a button with a paddle gun or push a paddle on a button gun. Maybe because I am left handed and always use my trigger finger, or maybe I just remember what gun I am running, I don't know but for me it's never been an issue, and honestly, I am surprised by that. Being left handed I prefer the paddle, but mostly because I prefer Hk's. I think the button is a great thing for the vp9 and hopefully brings more shooters to Hk.