They are better than cfl, but some LED do better. pl-l flouros are more efficient than the t-5 for their size. The 55 watt ones being the best watts to lumens. If you have a good set up you can get .5 gram per watt with flouros. A few have done around 1 gram per watt, but they are real experts with years of experience.
I use LED overhead and use 55 watt pl-l in the corners vertically. So you can mix and match too. Flouros lose their light intensity very quick, so if you can get the flowering plant within an inch or 2 of the light, that helps a lot. The 55 watt pl-l has around 10 inches of good light, this is for flowering. A reflector helps a lot.