I have ran both MH and LED. I recently had AI SOL's over my 125 for 2 years. I am in the process of upgrading my system to a 225 (my livestock is still in the 125) and in the upgrade I have sold my LED's and have gone back to MH. My alkalinity consumption with LED's was 1.1dKH per day. My alkalinity consumption with MH is 1.5dKH per day. I am not denying that LEDs can in fact grow and (somewhat) color coral, I just believe MH can do it better.
I was in the LED is superior boat for a long time. Probably denial to be honest. I spent a lot of money on my LED lights and at that cost I told myself they worked and were the greatest thing since synthetic salt. My tank did flourish under LED's, dont get me wrong. However since going to MH I can physically see better growth and the corals are richer in color.
Just my experience with the 2 types of lighting.