The Maggies will still have a limit on pure SPL unless you go for the big boys. That said, the 'limit' is much greater than it used to be. If you have a huge room and want 'balls', they still might not be the cat's meow for you.
I have a friend who has 3.6's with some serious mods, external xovers, MYE stands, etc. driven by 4 tube amps (2x160WPC bottom, 2x70 on top) and the VTL 5.5 preamp. Room isn't huge though. Plenty of juice to make them get up and boogie.
Just as an aside, I had the big Korato Anniversary over at a reviewer's place a few months back. He runs 1.6's in a room that's probably 20x28 with an 8' ceiling. It can, however, be closed off from the rest of the house with solid doors. We were both absolutely floored at the bottom end that combination was capable of. Seamless imaging, no 'OZ' effect, great depth, etc. In all fairness, he has them about 6-7' from the wall behind them and his seat is WAY away from any boundaries. Lots of room in that space to tweak them and get them just right.
Bryan