The 17 or my 21 are working great for me right now. Sold off all my other pistols.
I actually have pocket carried them. Deep concealment is not a problem. Only got made once when my kid knocked something off a store shelf and I had a short shirt on and bent over. Kindly got asked to leave. Not a place I cared to be anyway and have not been back since.
I thought the Sigs were cool and I did pick one up in a flash. Mistake it was. Full size is the way to go.
Now if I can finally narrow it down again to 9 or 45 will be in good shape.
I could never deep conceal my G21. Even my G30 would be tough to deep conceal. Normal concealment on either is easy. By normal concealment, I mean enough concealment to spend a couple of hours at a Simon mall without being harassed. Deep concealment is concealed enough that you can spend a day in a gun free environment populated with people trying to see contraband and not get made. I could never do that with any of my Glocks or 1911s. That little P938 is the only decent caliber pistol that lets me do that.
I'm not saying that the little guns are the best choice for every day carry (for me, that is) but am just saying that they let me go armed in situations I'd otherwise not risk carrying into. For EDC, I typically carry either a CCO sized 1911, a CZ 40P or a Glock 30. If heading to the city after work, that gets bumped up to the G21 more often than not.