Realistically, I doubt many people out there are going to shoot enough out of their pistols in order to cause parts to break. I know it is hard for me to slam 10,000 rounds through my pistols unless I am solely dedicating time and ammo to shoot that much in a short amount of time. With that said, I would say that unless there is a defective part on the pistol, you will find that these pistols are boringly reliable.
The storied history of the M9 being unreliable is an entertaining one for sure. I have been next to plenty active military at gun counters claiming they would never touch a Beretta because they saw the M9 slide break and hit their friend in the face and almost killed them. Sorry, but their is no way that kind of thing could ever happen again with the modifications that were made to every M9 and 92 series pistol in the later 80s. And also the claims of the pistol malfunctioning all the time is not something I would just take and run with. This is a military pistol after all, which means it is cared for in the worst way by some of the dumbest people when it comes to guns. Hardly any gun in the military is maintained properly or sees spring changes on a regular schedule. In a nutshell, take the M9 reliability and durability complaints with a grain of salt.
The other, and more concentrated issue for people who have used the pistol, is that the standard "F" version safety/decocker can easily be turned on while manipulating the slide. This is a true concern for untrained people, but is an unreasonable concern for two reasons. First off, after manipulating the slide, a simple sweep forward on the slide with the firing hand thumb would be enough to disengage the safety if it were to be accidentally engaged. The biggest reason this is a nonissue is that there are now G type conversions you can get that turns the slide mounted safety/decocker into a decocker lever only. Just these two things make the argument almost worthless, in my humble opinion.
However I feel about the matter, it is obvious that the new generation of shooters out there are starting to think that controls should be so low profile that they are virtually impossible to use. As with everything, you get extreme standards when coupled with extreme ignorance and inexperience. Most of these concerns for "larger" controls is that they can snag on clothing or be actuated unintentionally. I have rarely had that issue on a Beretta, but I have accidentally held the slide stop down on the Sig Sauer P200 series of pistols, the H&K VP9, and and caused the slides to not lock open on the last shot fired. Though low profile, the controls can still be put in a crappy spot. For those who give a crap, just thought I would give you some food for thought.
As far as the size of the 92 series, it is constantly critiqued as being TOO LARGE for a 9mm. Realistically, the 92 series of pistols are not much larger than the Glock 17, which is the standard they are judging this pistol off of. The The biggest part of the pistol is the slide, which makes it look ridiculously long. The grip of the 92 series is said to be too large for some hands. This is true if some hands are tiny, but it is not much worse than some of the other polymer offerings like the earlier Glock Generations. The biggest issue for people is reaching the trigger in double action mode, which I understand and have had issues with when wearing gloves, but it hardly makes a design inferior or outdated. Not everything is going to be perfect, even today.