Short answer:
I prefer to use service pistols for concealed carry. They're a lot easier to be accurate with while shooting fast than subcompact pistols are. Added capacity is a bonus.
How I got there:
When I first got into carrying, I did what everyone else these days seems to be doing: I got the flattest, lightest 9mm I could. Simply put, I prioritized "small". After some time with a Kel Tec PF-9 and Ruger LC9, I started to focus more and more on the "software" side of defensive carry. The more I worked on accuracy with speed, and the more I worked on single hand only shooting, the more I appreciated how horrible those subs are for practical shooting.
What do you want to be holding, if you ever have to shoot to live?
Key word: shoot. Not "draw/deter".
Once I began to prioritize performance over "small", I had to start sorting out how to comfortably carry by exploring holster and placement options. It didn't take long to figure out that I can very comfortably conceal and carry a Glock 19/23 in a hybrid holster, at 4:30, even in Summer clothing (Tshirt and shorts).
That is an excellent, well written post, and a great example of what I mentioned: that as you start carrying, you'll probably discover it is an experiment of sorts, and your priorities and preferences may change. I think that happens for most of us.
And it is therefore likely that you will end up with more than 1 carry gun. I'd venture that most of us, on average, have 2 carry guns: one tiny one for deep concealment when we can't hide a larger gun (ie, a pocket carried snub revolver or tiny auto) and a larger one we shoot better when we can dress around the gun.
And as RBid said, it isn't just gun. It is the carry method, and the equipment you use to carry that varies a lot as well. Lots of moving targets to hit
.
Have you given thought to how you will carry?
If you want to pocket carry, that will usually limit you to smaller guns that weight roughly 20 oz or less loaded. Usually. Same for ankle carry. On-the-Waistband (OWB) (and sometimes to a slightly lesser degree Inside the WB carry as well) generally allows for larger guns to be carried, and is probably how most of us carry. I'll sum it up as "belt carrying".
If you are going to belt carry, the size and weight of your selected weapon will have a significant influence on the belt and holster you should select. If the gun is thin, compact and light (like an aluminum frame S&W J Frame or Keltec 9 mm), you can get by with a standard off the rack belt of good thickness and possibly a cheapie nylon holster. OTH, if you are going to carry a big bad mama jama, like my S&W Model 28 Highway Patrolman which probably weighs close to 3 lbs loaded, it will require a good stiff gun belt that will distribute the weight more evenly along with a high quality holster made of leather or kydex.
BTW, for more info on different carry methods,
www.corneredcat.com, though geared towards women, is a good read for anyone particularly regarding carry options.
Just a few things to think about.