I mention T5 more because obviously T5 and halides are what I have the most experience with, as for t5 bulbs they're pretty similar across the board if you compare most of the popular bulbs, they all tend to produce slightly different spectrums but their par numbers are fairly close.
The big factor with T5 is the reflectors, the ballasts and the active cooling. There's a few comparisons out there that show the actual output numbers and it's surprising how big the difference can be.
Most people probably don't remember this but t5 went through the same struggles led did at first, everyone in the US said t5's couldn't keep sps alive and there was no way they would grow corals... Look at how things have changed lol.
It seems to me (I might be wrong here) but with led it's the diode that makes more of a difference than the driver, although after having the ATI Sirius led fixture I'm definitely a fan of reflectors over optics.