Couldn't be happier. The LED's are real nice; they're easily as nice if not nicer than the CREE's (I have a small fixture with a half dozen CREE LED's).
The best part is really the simplicity of the whole system. The drivers, dimmers, and power supplies are just way simpler than the buckpuck system in my opinion, as is the heatsink, which again, is unbelievably simplistic yet extremely effective. And its all modular, so if you have a driver or heatsink fail, they are independent and very inexpensive.
They are brighter than any light fixture I've ever seen on an aquarium period. Visually, they appear significantly brighter than MH and even moreso than T5HO, which was what I had on my previous tank. I won't be taking PAR readings or anything but I'm confident putting just about anything in there, clams, SPS, etc.