Depends on the holster; SmartCarry claims to work great for the fullsize, but the company's owner doesn't have as much gut to get in the way as I do. Mine works pretty well in the right pants as long as I don't have to sit too much, (if it shifts and I sit, it pokeskeyframe wrote:For those that carry a fullsize....
How comfortable and concealable is it?
Would it be a practical carry piece for me? 6'0 - 185lbs 32-33 waist?
) so it's relegated to carrying my Bersa or my old K-frame (both of which it can hide exceptionally well, BTW) until I can firm things up a bit. 
I have one of the Galco IWB cheapies for the 1911 that seems OK with a good belt, though finding the right position can be a pain, and IMO it would work better if I had gotten something with a fairly hefty cant, rather than one that wants to sit straight. SWMBO has ordered me a Coronado vest too, so I'll get to try that out soon, 
Remember that even though it's a big gun, it's still very narrow, which makes a huge difference in concealability. I also have a Taurus PT99 that is nowhere near as easy to hide as the 5" GM.