They work fine! I have 2x65W on a 37 gallon tank with softies, LPS and a single very hardy SPS. There's people that have had trouble with the 96W tubes cracking or otherwise having short lives.
gkrane,
I have the 2x2 55w over a 29 gallon. Everything is thriving. [no clams or SPS]. Very pleased with them. There was a thread on these a couple weeks or so back. You might try doing a thread search to see if you can find it.
They work perfect, I have 2; both 2-65 one of them is one year old the other just 2 months old, I've never replaced the bulbs ( I have to) but they still doing well.
I have the 2x26 over my 10gal. They work just fine. The thing I like most about them is the fact that in the instructions they caution about the change in light intensity and that there should be an acclimation process. Any company that goes to that length to sell equipment is, IMNSHO, AWESOME. HTH