Personally, to me its the best thing I have ever spent money on it.
Mine is set for 2 Halyards. Has 2 tracks and can run with Genoa too. It has a section that comes off to measure stay tension!!!! for real!!!!
It has a continuous line that furls either way, and the roller, which is like a thin large sheave binds into a "clutch" of teflon, so no accidental openings can occur.
As long as one of the loop ends is cleated, it goes anywhere.
I never ever heard anything bad about them, at all. Many friends are using them now and even some of the cruisers have them now too. They're simple light and efficient as hell. I am really happy to see all the World racers that come to my marina with the same roller.
During construction of my boat I saw and studied many brands. landed with facnor, because they made specially for my boat, and sent a rep to make sure we were OK with it.
It furls and unfurls easy, but you need to point into the wind with wionds above 25 knots. Opens and closes in 2 seconds.
I don't really see how they can jam up there, its a rotary disk inside another rotary disk, the inside turns, not the outside...so how can they jam up there?? I believe that's typical marina "badmouthing"..I highly recommend it.
The only problem I see, or saw, was it costs almost 3 times more. Because they customise it, and needs care and precise installation.
If you need more answers, please don't hesitate. You will need 2 cleats to lock the lines in the cockpit.