Help In Making Final Choice!!!

Hey Everyone!I made a post a while back about choosing my first CCW. I have since narrowed it down to a few options and was hoping there would be a few people who could give some pros/cons/vouch for one of these. I am comfortable shooting them, the price is good, and they all came recommended by people in this sub which is a good thing, I think.Here is the list:Glock 17 or Glock 19- I am going to be honest here, even after doing some research I am not sure what the big differences are between the two or what the different generations mean. I shot the gen 3&4 17, and the gen 4 19. They both feel good.If anyone can let me know if either of these are fine, it'd be appreciated. As well as put in layman terms what the differences are (I know I'm asking a lot, so I appreciate it).Smith and Wesson M&P 9 Shield- this gun also felt great and I like the smaller profile of it. I have larger hands and it still felt snug and comfortable. Don't have any complaints here. I do wish it had a higher mag capacity; but for the day to day ccw I think it will be fine. Also came highly recommended on this sub.Walther 9mm PPQ- honestly this one was my favorite. The feel, the trigger responsiveness were great. Hoping I can get some input on this weapon specifically.I am going to be making my final decision after one more trip to the range tomorrow to try these out again, so it would be great if there were any final pieces of advice/input.Thank you all so much for your help and for taking the time to read this.edit: for some reason I can't list 1,2,3. via /r/CCW http://ift.tt/2E9ebj9