Both are real good. It depends for what reasons you ask for and how you want to grow your plants . I use both in different veg rooms for different reasons. With my t5 I can lower and raise light and control real easy how my plants grow meaning if I want then to do a quick stretch I raise it until it get then where I want to tie them over with the node spacing I want. I tent to use my t5 lights on plants I want to train more. My MH keeps real tight node spacing and I still can do training but not as fast to change how plant grows for the light is stronger then t5 so plant stays tighter and harder to make plant stretch if wanted to. Now for heat they both about the same but I use cool tubes on my Mh. On a open hood Mh runs hotter. Take my info how you want. I hope it helps. I wish you the best