I think the thing here everyone has forgotten is the intensity of the output of the bulb over time.
Everyone knows that PLs are good but after the 5th month or so, the intensity of the bulb has dropped a lot. I am not too sure about T5s, assuming like all FL bulbs, there will be loss of intensity too.
As someone who has moved from FL to PL to 150w MH to 400w MH, I can tell you that there is a lot of difference and will never look back to having anything less than a MH bulb for a 2ft deep tank.
But that's just me! I am an advocator of MHs now.