compact bulbs work ok in small enclosures, like small Exo Terra's, etc. they give off a very narrow UV output compared to a much wider output from a tube, but this in itself isnt the big issue.
the problem with compacts is that there is lots of evidence to suggest that for a similar amount of UVB output compared to a tube, they give off a MUCH higher UV Index, which essentially means they are giving off more UVC. UVC is the most harmful form of UV, it is the cause of skin damage, sunburn, eye damage, etc. it is also of no real benefit to reptiles (or humans) to receive UVC exposure. in an ideal reptile bulb there would be zero UVC output, but substantially higher UVB output so that the UVB is similar to the sun in the wild, but with a lower UV Index than the sun.
compacts have their place, in small enclosures where a tube is hard to accomodate. but i think if you can get a tube in the viv, use a tube. none of the compacts or tubes give off sufficient UVB beyond a few inches from the tube for the majority of lizards from the tropics that like to bask in open sunlight at any time of the day. and if compacts are giving off more UVC then letting lizards get too close will increase the chances of problems. with a UV tube you can generally let lizards get to within a few inches with no issues.
im not using the term "compact" to include any MVB or Metal Halide bulbs though, such as Megarays.
0.0.2 Chinese Water Dragons (Physignathus Cocincinus)