The LEDs are very effective lighting in that they please the eye but, I can tell you that one 39w T5 is considerably brighter than 3 x 9w LEDs!
That is not a technical fact but an observation from my prospective.
The LEDs shine very bright & seem to penetrate the water well but the tubes offer a much broader beam that lights up my whole room through the tank glass.
However the combination works very well at showing off the tank & producing good plant growth.
I use the LEDs on their own for one hour before & two hours after the T5s come on - just for effect & the effect is superb, sending ripples of light into our room.
Unfortunately the LEDs on there own just dont seem to offer very good pant growth.