Ive concealed MP5K's before... as well as SBS and SBR's (although they were off body carry concealed)... and used to carry a govt model (full size) 1911 as my "duty" weapon at one time..
Its not that larger sized weapons cant be concealed.. they absolutely can.. its relatively easy for someone thats built like sasquatch (me) if you know what you are doing and have the right wardrobe to support it..
but...
for a 9mm.. or even the .40 variant (beretta 96), the weapon is considerably larger (in width, length, and height) than other pistols of equal or better reliability, functionality, and overall performance... which makes concealment more of a challenge.. and the pistol less desirable if CCW is the primary purpose for purchasing it..
overall length is the easiest thing to overcome... width and height however can be a serious problem for many people.. especially for women, smaller framed men, and/or skinny people).. good belt and holster or not, unless you are willing to build your wardrobe completely around your pistol, a 92F is going to present challenges for the typical 5'11", 165lb amercian male that another full sized pistol like a G17 or a 1911 (and many other pistols) will not..
again.. this can be overcome.. but it is something that should be recognized on the front end.. not on the back end, after you have spent $1000 on your new pistol, holster, gun belt, and spare mags, etc...
not banging on the 92F... Ive carried an M9 (army designation for the pistol) for a living.. and carried a 96D for a short while when it was the issued pistol at an agency I worked for several years ago... they are fine weapons... they are reliable, reasonably easy to maintain, accurate, etc.. and there is plenty of support for the platform available (every major leather and kydex maker int he US supports it, easy to get factory and aftermarket mags, etc..etc..)...
but they simply do not lend themselves well to CCW for most people... and are not even close to being a top 5 choice for anyone that has any serious amount of training or experience with firearms..