I got a jwrap right away for mine (actually I'd bought the original Mini and got 2 wraps) I noticed that the battery would not slide in easily - like it was catching on something. Also noticed the end cap was "difficult" at times. Appeared that the back seam was a bit out of alignment. I squeezed as hard I could and heard a little "click" The batteries go in a little better, and the end cap screws on more easily.
I have decent batteries, but nothing yet that I'm willing to drive over 10 amps on any build. It's fine for me, but I have about 5-6 mods in rotation at any time.
I think my toppers sit a little crooked, but not enough to bother me. Had I to do it all over again, I probably would have bypassed the Mini2, as I have plenty of other mods.....