I'll chime in here on the low tech end of this. My 90 gallon has the following lighting: 2 110w VHO actinics come on at 0730, 4 110w VHO (3 50/50, 1 actinic) on at 0900, first 2 actinics off at 0930. 2 actinics back on at 800pm, main 4 VHO's off at 9 pm, 2 actinics off at 9:30.
I have great luck with assorted soft corals, frogspawn, an LTA, 2 green BTA's and a huge Condy anemone, but SPS frags just bleach out, placement in the tank doesn't seem to matter much. I've had a few last a couple of months, but they still don't do well under this lighting.
Now my 40 gallon has 4 95 w VHO's, 2 50/50, 2 actinic that come on at 0930 and go off at 830 pm, and some sps frags do fairly well in there. I have a brown montipora cap that has more than quadrupled in size since August, Blue ridge coral that still polyps out and grows well, but acros...no go.
I have a pair of 250 w Metal Halides for my 180 if & when I ever get that set-up, and I realize that for a 6' tank, I probably need 3, but 2 will be all it gets due to some compromises with the bill payer lady.

These will most likely be supplemented with a pair of
60 or 72" VHO's.
I'm not really a reef keeper, more of a fish-o-holic who enjoys an occasional coral or 2 in my fish tank.