Well, I've only ever used Cree and Exotic LED's. It does seem like cree's can be used at much lower intensities for the same effect.
Here's is my experience over my 20 gal cube. I built on an 18" makersled heatsink. Pricey, but I have to admit, very well thought out and if you're not sure of LED placement, this heatsink makes everything very easily moveable.
I built 2 clusters, each with 3- Exotic true violet's, 3 - Cree 3-up stars, 1 Exotic ocean coral white, and 2 cree RB. And because I had them, I added 2 more single RB's in between the 2 clusters.
I run 1 RB in each cluster and 1 of the center RB's (3 total) as moonlights only.
I love my fixture! The OCW's and TV's give a full spectrum that I think many of the LED naysayers are missing.
I really need to clean up some of the wiring... A couple pics:
