TLDR warning. As if I have to, it's who I am.
been able to pair handguns and carbines of the same caliber a "few" times in my life.
.22, various and, well, various. It's a long list of pistols and handy 16" carbines.
.30 carbine. Inland M1 and Ruger 6"
32-20, Colt Army circa 1917 and '92 Winchester
45LC, S&W 25-5 8 3/8" and a Uberti Trapper 16"
44-40, Gen II SAA and a '73 carbine
357, Ruger Security Six and a Rossi 16" lever gun. I know many have had issues with this carbine but I'm not one of them.
44 Mag, Flat top Blackhawk and Ruger Deer Slayer
.45ACP, Ser. 70 1911 and Ruger Camp Carbine
See a trend here?
Since this was more along the lines of the thread ...
9mm, A large variety, P35,1911,P08,FEG, but no Glocks, with a Ruger Camp Carbine or an Olympic Arms 9.
I see a PCC as a more accurate pistol that shares pistol ammunition. I strongly resist loading specific rifle and pistol ammunition because of the ease of accidently mixing the two. At the very least the results would be unintended and at worst catastrophic.
Pros,
More accurate pistol
Shares pistol ammunition
Provides a longer sight radius
Provides a platform that you can hang optics, lasers, lights and siren from < /sarc
At 16" it's not that bad in CQB but wants a stamp (more on that later)
At 16" it's not unusual to pick up 100+ fps from standard (non +P) ammunition
Recoil reduction
Cons,
Could have had a .223/5.56, 300AAC/BLK, etc, in the same package.
16" isn't quite short enough and in today's climate wants for a stamp.
Magazines, today there are a plethora of options instead of the adaptors and proprietary crap I faced
Weight, for the weight of one unloaded PCC you could carry a second pistol or a bunch of magazines.
Other,
Add a second stamp for an integral suppressed barrel. Few are available but only lengthen the SBR by as little as 6". The downside is waiting on a form one if you're going to build your own while several alphabet agencies look up your skirt for the better part of a year or finding an integral suppressor barrel and paying the "luxury tax" and waiting more than a year. In any case you get a reasonably short PCC for an extra $400 in stamps plus twice the cost of the weapon in home machining or off the shelf suppressor.
last words
I only have the PCC's mentioned above because I could and did over a period of decades. I don't think I'd ever use one as a dedicated home or personal defense weapon. I have many other choices. I have carried a PCC and its paired pistol in the woods outside of the hunt just to lighten the load and share ammunition.
You are fortunate today that most 9mm AR pattern rifles use common magazines. A few have even gone beyond blow back and are delayed-locked. Some are even sold as pistols and can be braced rather than stocked depending on which way the flag waves. Still, I'd evaluate want verses need against desired function. The real question isn't pistol or PCC it's what you are trying to achieve and what is the best tool for the job for you.