I recently found myself in that very same place. HPS, tried and true, but hot and power hungry. LED has the big upfront buyin and is great, but will get better yet as materials improve. I went for the LEC 315 ceramic metal halide. It's been hanging a few days and so far so good. first pistils April 1 and I'm seeing more everyday. ABSOLUTELY SILENT. ZERO HUM. Full spectrum (4200k bulb). Low heat and fast startup. 15 inches to scrog canopy, penetration may be an issue for some, but not us scroggers. Cheaper than LED but more than HPS. Light output similar to aircooled 600w HPS. but without the glass that filters out UV. High Hopes, High Hopes. Still too early to tell, but massive upgrade from my starter rig, 13 x 16 watt led house lights. I have 2 9inch fans blowing between the light's bottom and canopy on the low setting. Smallbox, 50 cu ft, 4x3x4. Good luck.