Depends on how deep your tank is Steve - what size do you run? You can always get creative with coral placement and make the best of it, and hang the fixture as close to the water as you can get away with. There was a 75gal tank of Evan's running 2x150 DE and it was one of the best-looking tanks around - loads of nice SPS. I'll see if I still have a picture.
Here it is, the one on the left.
