My own Kel-Tec pistols, a P32, P3AT, PF-9, and P11 have all been reliable over the years. The P11 has a trigger-pull measured in inches rather than pounds, as it goes on forever, but it's always fired.
Anyone can have personal preferences about weight of gun vs. caliber. I respect that. However, the idea of carrying a small gun is to pack enough power into it to make it work. You'll be carrying it literally thousands of times longer than you'll be using it. When the time comes to use it, heavy or light isn't a consideration measured in ounces of difference. Until then, though, even a few ounces can make a difference in when you'll carry a gun.
The 9x18 caliber has not garnered any type of record in combat, or police work, the two areas where records are usually kept. It does, however, make an excellent execution weapon, against a non-resisting person. That appears to have been it's largest use behind the Iron Curtain. There haven't been even anecdotal stories of it's use in Afghanistan or Chechnya.