i have a a Hagen Glo 2x 39W on my 29 gallon and I see better growth than i used to have with my 2x 65w CF coralife fixture. Same plants, same ferts, same position on the tank.. etc.
this is not scientific at all, of course, just anecdotal. My vote is to get the t5ho rig versus the CF fixture. The t5 fixture was much smaller and the bulbs were cheaper at my lfs.