Over the years I've owned a few G36's, not to mention many other Glocks. I will say that the G36's pack well due to it's slimness, however, the slide is the same thickness as a G26/27 , only the grip is slimmer. If you looking for a real compact pistol, look at the G26 and G27. I'n my experience, I have found the G36 to be stout on the recoil, and sensitive to limp wristing. I question it's reliability due to it's lack of slide mass. I dont care how many people put thousands of rounds down range with their G36's that's great that it works for them, that;'s what really matters. If you aren't so concerened with the slim factor and just want a compact 45 acp, then the G30 is a completely different aninal than the g36. It is more controllable, can be more accurate in my opinion, and more reliable.
In summary: If you want something where concealability is a primary factor, I would look into the G26/G27. If caliber (45 acp) is the primary factor, I would seriously consider the G30 as it is a real winner in my opinion.