Not far enough. A friend of mine here in Corpus, after two months of a solaris 72", is changing it out to dual 400w MH. SPS just barely surviving under the light. Lots of factors to consider and many lights different and flow, water quality, hight from water, tank depth, etc. But, I can tell you in his tank (tall) the light doesnt work. He has some coral from identical mother colonies that I do and there is major differences. He also was in contact with many people from RC expressing same thing. LPS and softies do fine, SPS (with some exceptions) seems to barely survive or worse. Out of curiosity, using same PAR meter I did measurements at equal depths on my two tanks with MH vs. his tank and the #'s were about 40-50% less with the solaris. Not scientific, but same meter on same day.
I was hoping for a different result for my future tanks. So, IMO not there yet.
mark