i originally started out with an eclipse3, its the 15H tank with black hood.
here are the problems I had with it:
~trickle filter caused high nitrates (and they're expensive)
~no room to add skimmer (without geting out the hacksaw)
~restricted access to top of tank (its not easy to take the hood completely off without soaking yourself or your floor)
~insufficent lighting (is fine for freshwater)
~poor water circulation (most circulation is at the top of the tank)
It will make an appropriate hospital tank, or even a sump if you wanted to drill some holes. In any case, i liked my eclipse for freswater cichlids, but not for a SW tank. It will serve as a good QT / hospital tank though.