The M&P 9, that's my Dept duty gun, and It's also one of my carry guns. Feels great, points naturally, the trigger is not too bad at 6.5 pounds, and the 17+1 capacity is nice to have, although I agree with Mr. Roscoe's statement that the only rounds you should ever need are the first two or so. I got mine as a LE package with night sights and 3 mags (+2 free from S&W) for about $540.
My Dept only indemnifies us with 9mm... :?, so my other carry is my Kimber ProAegisII. I love 1911s, and I preferred the 4" barrel. It cost me twice as much as Smith, and has about 1/2 the capacity.
Hks, I consider them to be some of the best weapons in the world... but the prices are kinda... ridiculous. I also played with a P30 and USP 9 when I was looking at the M&P 9, and they were phenomenal weapons, but I personally couldn't justify spending twice what I paid for the Smith for a Hk polymer that in MY opinion, did the same job. There was no discernable difference with accuracy and function, and reliabilty, and they both felt fine in my hands.
I have Hk pistols myself, actually my first pistol was just a eensy, bit overkill, a Mk23
. I paid an arm and a leg.. but that is arguably my favorite pistol in my collection. It functions flawlessly, 12+1, and is in NO way concealable :} However, looking at you list of prospects, it doesn't seem like you are going that route.
The Beretta is a fine weapon, and even though I would have loved to have had a .45 commander as my sidearm when I was overseas, the M9 never failed me. High cap, great sight picture, and not too expensive. The only berettas I have are a 8045 Cougar, a PX4 9mm, and a CX4 in .45 that conveniently uses the same mags as the Cougar. All function flawlessly, and the PX4 surprised me with how accurate it was. I also personally love Beretta's rotating barrel lock.
Glock.... I have never been a Glock person. (Gasp!! :shock
I just never liked how they felt in my hands. The trigger isn't for me. Having said that, I know they are great weapons, so if you like how it feels and shoots, go for it.
Going back to the M&P, if you wanted work done to it, there's a couple of well-recommended smiths that work on them.
http://www.burwellgunsmithing.com/ is one, and I hope to have him do some trigger work for me in the near future
http://www.bowietacticalconcepts.com/ is another. I've no personal experience with them, but they come highly recommended for polymer pistols.
Like others have said on this board, I think the best thing you can do is go out and try to physically handle the guns you're thinking about. See how they feel, how the trigger is for you, and if you can fire them, even better. Good luck with your search.
Vin