It depends mostly on how hardcore you are towards SPS.
I have experience with 150W DE 10K Icecap , 250W DE 10K Ushio, and many Single ended 400W such as 10K Ushio and 20K Radiums.
I will first start out by saying, The is no perfect lighting for everything. All wattages/kelvin have strengths and weaknesses. Ballast and reflectors also play a role so not always comparing apples to apples.
I was actually pretty impressed with 150W DE setup and does pack a pretty good punch for the wattage. However, it is only about equal or just slighter brighter than a 175 single ended so if your expecting it to be as high as a 250W single ended it is pretty much an exaggeration.
When comparing to my 400W 20K Radiums it is hard to say which is better as the corals adapt and change to different colors. For example: I picked up about 10 wild caught SPS the day they arrive here from LA importers and for most the 150W DE seemed to hold pretty true to the color ( at least what it looked like by the time it arrives in the US ). After being under the 150W DE in my quarantine 40g breeder for 4-6 weeks, I placed them in the show tank with 400W. Most all of them got brighter more colorful but none really stayed the same color as when I first got them. Those that were light blue all changed to either purple or green under 400W 20K Radiums. For some I preferred what they looked like under the 150W and some I liked the way the Radium colors them up. Which one best represents what it would look like wild caught who really knows because I can only compare to what it looked like by the time it reached MN........
If going to be mostly a community tanks with a wide variety of coral types, it is a fine choice. If you leaning more towards SPS then the 250W double ended or a higher K 400W such as 10K Ushio or Radium ( my personal preference ).
If you haven't seen/read this article, I encourage you too.....
http://www.advancedaquarist.com/issu...2/feature2.htm
