if it helps any, this is my honest assessment per major reef site on the # of people using sl28:
-Reef2reef: perhaps 2 at most, maybe 4 and I'd be astounded if four people total on this board actively use it.
-nano-reef.com: I'd bet none... surely those guys are not buying it but let's allow for 2 max users of it however in case someone wanted to experiment
Reefcentral, likely 200 users of sl28.
if I'm wrong in any of my guesstimates above/lemme see the links showing more % use than guessed.
the hobby is mainly getting by without it, its a very old product too I remember asking Randy about it in 2002 if I'm not mistaken. On reefcentral.