The Greenlee hole saws work reasonably well, but there's plenty of room for improvement.
Problem #1 for the Greenlee saws is that they come in several sizes that are very close together- it's quite easy to pick the wrong one, and make the wrong hole. Make REAL sure you have the right one.
Problem #2 is the ease with which any large hole saw binds. This can be hard on the wrists- and the head, if you're flipped off the ladder. When cutting through plywood, I've had that little 'bind' break things inside the big, fat right-angle drill. (More of a piglet than a hog!)
Problem #3 is the enormous amount of dust created as you drill. Better have someone hold a HEPA-filtered vacuum next to the saw- and a tarp under you.
Still, I cannot think of a better way. Maybe the fancy saw covers work; the cheap ones sure don't. Someone suggested cutting a basketball in half, and I just might try that; I can even add a vacuum hose port!
I can't see how to use a multi-master to make a round hole in the ceiling would be much of an improvement- though the muiti-master is the cat's meow for rectangular holes in walls.
As for the Ideal cutter ... when they say 'drywall' they're only kidding. Even with ceiling tile, it's one heck of a dust maker. Using the plastic packing as your dust collector, as they instruct you, is some marketing guy's wet dream. The most I would use that for would be to mark the ceiling for guiding another tool- like a saber saw or rotozip.
As for the rotozip .... here's a hint: Don't use Rotozip bits! Instead, go to a machine shop supply house and get solid carbide milling cutters that are designed to throw the chips / dust DOWN, away from you. These will push a large amount of the dust into the wall cavity, rather than filling the air around you. Expensive, but worth trying.
