Have you tried both and compared? IMO it will out perform, don't write of the t5's they do perform really well. The lumens per watt are nearly the same, less heat, and you can mix the bulbs for a broader spectrum. They are both good lights though.
JMHO
T5ho puts out around 90 lumens per watt at most mh puts about 100. I can put the light on the canopy no cooling nothing. If you air cool your mh that's more electricty therfore the t5 is more efficient. The individual banks are being reflected straight to the plants. They are not the best if you...
as many as you can afford get the highest wattage you can find
6500k veg
2700k flower
it doesnt hurt to mix up the spectrum. Get the y adapters put two of each spectrum in each socket