Carried a 5" 1911 for years and now, a full-size M&P 9. A full-size pistol is going to be generally more controllable, have a higher magazine capacity, and in some cases, be more reliable. The downside is that it’s obviously not going to be quite as concealable as a compact model. My preference is to carry the largest size pistol that I can reasonable conceal in whatever platform I choose.
Full-size pistols I’ve carried in a traditional 4-5 o’clock IWB position:
[ul]
[li]Beretta 92G
[/li][li]Beretta 92G Brigadier (Elite, Elite II)
[/li][li]Beretta 92G Vertec
[/li][li]SIG P226R
[/li][li]SIG P220R
[/li][li]SIG P220ST
[/li][li]S&W M&P9
[/li][/ul]
AIWB, I’ve carried:
[ul]
[li]S&W M&P9
[/li][li]HK P30
[/li][/ul]
All it takes is the right holster, right belt, right clothing, and right attitude.
I carry a stainless P220 Elite Match year round in Mississippi. In the summer, I have a Milt Sparks Versa Max for it. In the winter, I carry in a Comp Tac belt holster. Typical clothing in the summer is a sleeveless t-shirt covered by a button down shirt left open with some weight in the corners.
Glock 17.
All day, every day, all weather, any temperature. This is in addition to 1-2 reloads, a 2-cell surefire, a folding knife, and a can of OC.
I currently carry in a Sidearmor IWB at 4 o’clock with a 15 degree cant. I’m considering trying AIWB if I can get an appropriate holster.
The only situation I’m regularly in where it’s not at all practical to conceal the G17 is the gym. It’s a compromise I’m comfortable making for 4-5 hours a week, but I’m toying with the idea of getting a Ruger LCP for this reason.
I carry the G17 because it’s what I train with. I can’t imagine putting ~6,000 rounds a year through a G17 and then carrying a J-frame just because it’s easier to conceal.
This bears repeating.
Used to carry a Glock 17, now I carry an M&P (occasionally the long).
I’m a big guy so I’m less constrained by size and I just prefer a full size grip.
I invest heavily in Hawaiian shirts for cool weather. 
I find IWB carry to be uncomfortable so I if I absolutely have to do it then I carry my Kahr K9. Most of the time I can get away with my 4" 1911 in a Rafter S OWB holster. A lightweight t-shirt gets tucked in then I put a button down or polo over the top.
Glock 17 IWB RC 5 o’clock
spare mag/surefire 7 o’clock