I carry a G21SF under a t-shirt - no problem (5.10’, 200 lb.). I prefer carrying a full-size gun because it allows me to get a much better grip during the draw…my problem with compacts is probably my gut! YMMV
My preference would be for the Glock 19, but I’d be happy and confident using a Glock 17. The truth is that, with a proper concealment holster (I’d go for a canted leather IWB holster, with widely placed belt loops), and a good firm gun belt (even something as simple as a Wilderness “Instructor” type belt), the Glock 17 can ride very discreetly, very comfortably, all day long. A good point was made about the Glock 19 being a great example of a CCW. That said, I think it would also make a great impression on students to demonstrate to them that the even larger Glock 17 can be effectively and comfortably carried, with the use of the right gear. You don’t have to be a big guy to conceal either of these sidearms. You just have to be a properly informed and motivated guy.
um-hmm… if I was only going to get one…
but he already has a G36 for CCW. I would pair this with a G17 for the purposes he described. but that’s just me…
I would choose the firearm that I can shoot better which may be the G17 but you are the only one that can decide. My guess is i would probably shoot the G17 better being that it is a full sized firearm.
As far as CCW goes unfortunately you are the only one that can make that decision because everyones body is unique. I know people my size that carry G17s and people that are actually smaller that carry full sized 1911s. I think a G34 for me is pushing it but it is almost possible with the right holster.