It's great stuff. I feed it to anyone who will eat it. Some of the larger fish don't seem to see it always, but the smaller fish go nuts over it. My anemones will even catch pieces of it. It really does seem to bring out the colour contrast in those who eat it. I even feed the flake to my FW fish and the colouration of the clown loaches (reds) in particular has picked up.
My only complaint is the freeze dried product really, really wants to float (and soaking it doesn't really change that). You have to feed it in a very high current to keep it suspended. Unless you have fish that will pick it off the surface (none of mine will). The flake product and the frozen product don't have this issue.
Another thing I've noticed is that I have to feed stupid huge amounts at one time if I want to see my SPS catch it. Smaller amounts ... well I'm sure they catch the occasional piece ... I just don't see it when it happens unless I make the tank one big Cyclopeeze blizzard. (sounds like a new DQ flavour
)
If the size of the frozen is a concern (it is a bit pricey) then the thing to do is get a bunch of people together and share a brick. It's well worth getting your hands on some.