I have both a T-6 unit and 400W MH bulbs. The MH bulbs are hotter and use more power but seem to do a little better. My T-6 unit has to be closer to the plants to be real effective but overall they are both great...Heres my link
Hydrofarm T5 4FT Designer Fluorescent Grow Lights - Plantlighting Hydroponics & Grow Lights