I have had "shag", our monster Carpet for quite some time, color is great and hes a champ for movement and curling up and fluffing out. But they get enormous, ours is nearly 2 foot across when spead open. They do grab everything they can, fish, other anenomes, your hand.....not much a big deal to have a tenticle or two stick to ya but if you let one stick any real amount of surface area on ya they will leave a mark that will hurt for hours and its like trying to pull velcro off your skin.
Size- they do get large quick, not just space but they get expensive to feed.
Flow- they do like flow, and lots of it
Aggressive- one of if not THE most aggressive anenomes.
Light- they say huge light, but I really think thats in the eye of the beholder.
Hosting- since they can get so large and they are so active, they are great to watch. they are great hosts too. Just make your choise wisley because of thier grip/aggression/and potential size.