Weird, the video is only 3 weeks old according to the caption (4/10/14). They must have either spent a fortune to upgrade all at once or they are just in the process of changing over?

Those High output (T5 HO) seem like overkill for lettuce, but everybody has their own ideas about that I guess. Using a PAR light meter, the regular T5's appeared to put out plenty of light for lettuce and other leafy green vegetables as long as they aren't too far away from the leaves.

We have T5 HO on our citrus trees because the light needs to "reach" further to get to all the leaves on a tree; but are planning on using regular T5 for everything else.