4 bulbs is worlds better

. I actually have a 36" 4 bulb T5HO that I'm debating getting rid of.. it's an odler Nova fixture, that I've had 5 years, but only used for about 6 months and had just replaced the bulbs from OEM all 10K to 2 ATI 10K and 2 corallife actinic (mostly purple - high nm light). (maybe have 1 month of use) PM me if your interested in it.
I loved my T5HO in the above configuration running 6 hours a day full light and 10 hours of actinic. (2 hour lead on the actinics either way). Great color and nice growth
I swapped to MH when I moved up to a 48" 55gallon, and I find the shimmer and more natural look of the MH output much more aesthetically pleasing personally. Though, I am debating going back to the 4 bulb T5 for a few reasons. A)Quieter, B)Less electricity, C)less light spill with some shielding added to the fixture, can't do it with MH, LOL D)HEAT. That last one wasn't a problem on the 55G, but the 29 doesn't seem to have enough water volume to resist the heat as well, even with a pump circulating very near the top to help keep it from being a problem :/