I carry full size service pistols.I am carrying a Sig P226 9mm dailey concealed with no problems what so ever.I prefer full size service pistols and have no use for pocket pistols except for a back up piece and then I prefer J frame revolvers.
I can conceal a full size pistol with no problems too, but I choose not to dress around my guns. I would rather wear what I want and carry a compact 9mm or .380 than have to dress around my gun everyday. Sure it's doable to conceal a full size pistol day in and day out, but there's no denying it's easier to conceal a smaller gun.
As far as J frames, I carried a model 60 and 640 for 3 years and currently don't carry either. I shoot auto's better and conceal them easier.