First I live in Maryland where getting a permit is a non-starter
At the moment, that statement is true. The 2nd Amendment Foundation is
pursuing a case that has the potential to change that. Also, are you part of
Maryland Shall Issue?
I lived in Baltimore briefly in the mid-1990's. I had one incident in which two men chased me into my apartment, then tried to beat the door down while I was on the phone with 911. By the time Baltimore County arrived 22 minutes later, the assailants had left. I have no idea what they wanted.
In any case, the responding officers told me it was a good thing the assailants hadn't broken through the door, because if I'd have shot them, I would have gone to prison. No castle doctrine there.
I was aware that Maryland had a structure for issuing permits, but my inquiries were stonewalled. Ironically, several years later, I spoke with a retired Ann Arundel detective who said, "heck, you should've called me. I coulda gotten you one." Lovely.
In response to your original question, most of the guns I carry are service-size pistols. Simply put, I don't shoot J-Frames and pocket .380's very well, and I'm not going to carry a weapon with which I'm not competent.
That said, I usually carry a medium-frame revolver. Automatics are a Sig P220 or a 1911. I don't do IWB. The right holster, and most importantly, right belt make a difference. So does presentation. I don't wear gun-related clothing, and I'm a fairly easy-going sort, so nobody really thinks to scrutinize me for bulges under the clothing.