Furlers have been around since the 30's and probably before that. As I understand it, Ted Hood -- of Hood sails -- may have been the first to figure out how to get the headsails to roll evenly and "reliably" onto a foil (the slotted tube that holds the sail). He was the one who added a swivel to the top of the unit.
Our Ariels have had a similar system on them from the beginning -- on the mainsail. Although the roller reefing on our booms was never intended to roll up the whole sail, the sail "furls" around the boom like a flag furled around a flagpole. Mainsail roller-booms work, but it's difficult to get them to roll evenly, so the sail shape is poor and most of us have gone to slab reefing our mains.
Early headsail furlers had the same problems: awkward, unreliable, and crummy sail shape.
Design changes and new materials have made huge improvements in headsail furlers -- to the point that they are reliable, almost maintenance free, and can be used to reef in about 30% of the sail while maintaining acceptable shape (if there is some material in the center of the luff to flatten the sail). Off the wind, sail shape doesn't matter as much.
I have always prefered hanked on sails, but my wife has always prefered to keep people off the deck when the wind is blowing hard and seas are up -- she's never liked to have either of us on the foredeck herding a flapping genoa in heavy conditions. So, I relented and got roller furling.
I made a 130 genoa with a high clew, put it on the furler, and it really is slick. I'm going to add a heavy working jib that will reef to a storm jib for the furler, and a big nylon drifter to hank on to the bow roller, and that'll be it.
But remember, as Mike said, when I want to change sails -- I'll still have to go forward, and it will be a lot harder to do compared to hanked on sails. So, I'll try to choose sails before I go out. Fact is, the furler makes sail handling very easy, quiet and without much anxiety -- all from the cockpit.
It's all trade offs...and I've gone over to the other side. I'll keep the furling/reefing system.
--Dave