I have the 125 watt CFL from Hydrofarm with the Hydrofarm hood/socket. It's bright, but it has a tiny footprint. I use it for an area the size of a cut tray (10-inches by 22-inches I think). Your 4-foot t5s are going to have a lot better coverage. I think I would like the hydrofarm (and all CFLs for that matter) if it were flat. The fact that it's round makes it better for hanging vertically than horizontally. It's better for side lighting than overhead. But that's just my opinion.
If I were shopping for a new light today and I had the choice between a 2-foot 2-bulb T5 and the 125 watt CFL, I'd choose the T5.