I have a 37 gallon cube. Been up and running four a couple years with LED.. LPS was fine.. a few months back I started getting SPS fever.. growth sucks... started researching.. I'm about to upgrade to a much bigger tank (225g).. SPS only. I want to do it right. I started researching. I'm sure it may have already been pointed out somewhere in this enormous thread.. A few days ago I stumbled across an article published in January of this year.
I think we can all agree that Sanjay Joshi knows more than most when it comes to keeping a reef tank and especially lighting one. He had experimented over the years with LEDs over his smaller tanks. 2 years ago he replaced 3 400w MH over his 500g tank with 8, yes 8 Radion Pros. Right from the start.. cost is ridiculous, energy savings is negligible.
Sanjay is an expert, he utilized arguably the best LED tech at the time (and most expensive) and he can get about 80% the growth of his MH setup with most corals.. and some species he points out.. not even close to the growth of MH.
https://www.reefs.com/blog/2016/01/05/leds-500-gallon-reef/
If that's the best that Sanjay can get out of LED with his knowledge and $6k of top tech lighting I'm sure not going to bother with it. I'm going MH on the new tank for at least the first couple of years until I have a thriving reef.
I guess people need to decide what their goals are. I want to grow SPS frags into colonies as fast as I can and I'm willing to sacrifice electricity, heat and bulb changes to get my reef grown. Maybe I'll look at LEDs again in a couple of years when I have a mature reef.