Hello,
I always find this topic as a endless debate lol. Personally I have not owned a t5 or mh on my own tank. The main reason is that the three lfs don’t carry anything but leds. Even if one was to ask, to special order etc they won’t. Getting advice on what to get on these is even more rare. When I first started I honestly didn’t have a clue that there were online forums. It also doesn’t help the fact that Idaho is 100 years behind most states in about everything.
When I was working with aquariums their huge 500 gallon tanks and larger they always used mh. The smaller ones I have seen mostly leds. But in all honesty, trying to figure out which light is better for a reef tank is trying to argue what’s better ford or Lincoln. (Yes I know they are both made by ford

). Yes there are some amazing aspects for each light, and kind of light. But true hobbyists, usually end up doing what they like the most.
If people want to tell me that my tanks looks horrible so what it looks horrible. But as long as I like it then who cares I don’t have to justify why I’m doing something. I don’t need to because I’m already doing it lol. If there comes a time that I want to change things then I can always do so.
I have seen some amazing tanks with every type of light out there and it’s neat to see how creative people can get. But again (and I’m only speaking idaho), your lucky to find a salt water store other than in Boise, not alone that they carry any supplies for t5 or mh. There is only one store that has an mh setup and they are (poseibly) switching over. So it does depend on where one lives, when I was in Seattle, yes there were options for the others. The only problem was they were not allowed in dorm rooms

.
As a point of fact about the only thing really in common about these lights is the fact people enjoy saltwater reefs for what ever reason they have, (and they are all valid, from power growers to those who love the old school systems that work, to new techy things).