Besides Humbolt's grows I haven't seen many cfl grows that use nearly enought lights, and this method is a large force in the grow journals right now.
The little plants do fine under them, up to 6-8" i'd say, but as they get bigger you just can't service the majority of the plant, I've tried hanging cfl's with a bit of window screen around each one them at the side of the plants, and you'll still get burned leaves, how can a 42W light be so hot???
Anyway I used to use all of my time just moving and repositioning lights constantly to keep them close but avoid burning. What a waste of time.
Eventually I just bought the proper lights, and the difference is spectacular. When I look at the room that the plants are in now from down the hall it looks like the sun is setting in the room. That is a sweet feeling.