The Last Glock I bought (I have owned about 15 of them over the years) a model 19 third generation, neither magazine worked properly, I had to replace them.
Just like the first Glock I bought about 22 years ago. Lousy mags. I know which magazines to buy for my 1911's that work reliably. I obviously don't know for GLOCK.
I find reliability is more often a factor of who is shooting the weapon then the weapon itself. There are of course "stuff" that causes new weapons to jam that are beyond the shooters ability or capability to tweak. Most, not all can be solved by the shooter with a decent "set up" break down, tweaking and inspection. With proper lubrication for the given weapon, and an understanding of what generally works and doesn't.
56 years of shooting, started competing with my 22 rifle in 1958 and 43 years since my first real fire fight do give me a bit of an advantage. I have continued to compete in different venue's over the years. As to handguns it has been Bullseye/2700 USPSA, IPSC, IDPA, a bunch of local stuff, Bowling pins, rimfire, centerfire and hunting.
Most mainstream guns work fine out of the box Glock, SIG, HK, Colt, Kimber, Springfield, Baer, Ed Brown, Wilson, S&W, Ruger, CZ, and a lot of others that are not coming to mind right now. If given a choice to choose, I personally would probably take the HK. I am not a fan of the USP but they have proved to be reliable, I like the new P series, UK45, HK45c, P2000, P2000sk, P30, P30L.
This is like dancing on the head of a pin.
One thing I do find fascinating, is the folks who do not like, or rundown a certain handgun. Most often without specifics, or at best anecdotal "evidence". LIke with my Glock 19 coming with magazines that didn't work. Do I believe all Glocks are lousy, nope. I just understand them for what they are. Only the inexperienced person thinks the gun on their hip can't or will not jam. They all can, if the owner/carrier doesn't do their job.
Maintain your weapons, clean them, inspect them, lubricate them, and replace the parts that need replacing BEFORE the weapon jams. Yea all really radical stuff.
Oh, and for the OP. I am, have always been Prejudiced by facts. Opinions are like as..........
And based on the mission, right now I would probably most likely go with either a HK45 or S&W M&P 45, or in 9mm an HK P30 P30L. Still ain't figured out what the 40 is for. Obviously a lot of other folks have.
Go figure.
Fred