Wick Alcohol Stove anyone using one.

Just been reading and youtubeing about wick stoves and they seem to be very very fuel efficient and can boil 2 cups of water in 5,6,7 minutes, just wondering if anyone here has built or use one, would like some info about them.
The wick stove seems to need no preheat and you can just blow it out when your done, not sure how long the wicks last or really how much more fuel efficient they are though, but better than a coke can stove or a normal Alcohol stove I would think.
Has anyone had any experience with wick stoves ???
/PS their must be some drawbacks to a wick stove, right !!!!!
Cheers.
The wick stove seems to need no preheat and you can just blow it out when your done, not sure how long the wicks last or really how much more fuel efficient they are though, but better than a coke can stove or a normal Alcohol stove I would think.
Has anyone had any experience with wick stoves ???
/PS their must be some drawbacks to a wick stove, right !!!!!
Cheers.