I remember Asylum ticking for something around 500±50 as well.

As an ability, Asylum is a nice addition when a tank takes repeating damage from something and a dose of Regen isn't enough. Same goes for placing the bubble around DPS that I can't be bothered to heal properly. Right now my biggest issue with it is that I keep forgetting I have it. Assize is easier to remember because it plays a part in MP management.