The T5 vs. MH debate brings me much pleasure
I run a 6 bulb tek on my 90 and have been more than happy with it. After using MH I just prefer the T5 and I would have a hard time going back to MH.
I have kept SPS under them just fine - growth and colour (allthough I am out of the SPS game, after my last tank crash) I have three clams that are very happy at the bottom of my tank.. and these are cretures that I had always read needed at least 250W of MH to thrive.