I am 5'08, 155 and I carry a USP45 in a Galco shoulder rig and a G27 in a small of back holster by Dillon leather. I carry this under a Hawaiian shirt usually. No printing if you carry correctly. I will sometimes carry the G27 in a Galco ankle rig. I carry either way. If I can pull it off, anyone can. All my cop friends and other LEO's I come into contact with have no idea I'm packing until I show it. This includes a USSS agent in the Phx area that I met. He is an expert in detecting hidden firearms by sight.
I will also carry the USP45F in an IWB Kydex rig that I designed. I wear XL T-shirts and it conceals very well. I have been carrying a USP from early 1995 up until late last year, when I started carrying my P220.
I also had the USPc 45 and sometimes I'd carry both the full size and the compact together. I found myself packing the full size most of the time. Sometimes I'd carry the USPc as a back up to my 3" model 29 .44 mag revolver. I loved that model 29.
I hate hearing that someone needs to carry a Raven .22 because everything else is too big. Learn to carry your firearm correctly and this won't happen. You'll be able to pack an M4. And I have done that as well, thank you. Think Trench Coat.