You switched over because you were afraid of fire? Even though I have had a house fire (they are devastating), I am no more afraid of leaving my lights running than I am of leaving my furnace running. Most grow room fires are caused by overtaxing your electrical system or using extension cords of insufficient gauge. Please make sure that your electrical system will handle the job it is meant to do. A dedicated circuit is always a good idea. I can think of fewer things less pleasant to come home to than a home destroyed by fire and police waiting to take you away.
I have a Mars II 700W LED and an Apollo Purple Sun 768W cob light (that was loaned to me by a friend). The Mars is hardly worth the effort to hang IMO. I had the 2 lights in a 3 x 6 closet and the Mars II just sucked. The Apollo was better and I am going to try it again in a smaller tent by itself. The Mars II may work okay to veg small plants, but I love my T5s so much that I will probably continue to use that. While I found that the LEDs do not put out as much heat as a HPS, they do run hot and you will still need a centrifuge type fan. In the winter, I find I need the heat from the HPS...especially now. Going through a nasty cold snap. Haven't seen temps over 32 for a few weeks.
Hamster, glad you are liking your LEDs. I ran the LEDs for 3 flowering cycles and just didn't get nearly the yield that I got with my HPS. I do have to say that the buds grown with Led do get really frosty, but I just never got nearly the yield.