I have several semi-auto pistols in two calibers: 9mm and .45 ACP. Up until the summer of 2015, I solely used .45 ACP (that translates to over 31 years). I strictly used DA/SA pistols (sorry, don't mean to offend the 1911 folks. Fine guns, those). Anyways, so, last year I bought my first 9mm (again, DA/SA), then in January of this year (2016), I decided to see what this "Glock thing" is all about - I bought a Gen 4 Glock 19. I now shoot the 19 more than all of my other pistols combined. I shoot it better than any of my other pistols. The darn thing just works. It has replaced my daily carry gun on the nightstand (though it is only the third go-to-gun at night time, beaten out by my 12ga and AR15). However, my daily carry gun is still my Bersa 45 Thunder UC. I use appendix carry, and, for me, the Glock 19 is just a tad bit too big to be comfortable for all day concealed carry, appendix style. Having said that, if the 19 were comfortable enough, I would not hesitate to make it my first choice for appendix carry. Again, I can shoot the 19 better, faster, cheaper, and it fits my hands (medium back strap with beaver tail) like it was made for me. Additionally, the trigger re-set is fantastic. So, in summation, I shoot a lot more 9mm than .45 ACP nowadays, and I have become a Glock fan.