I do like them, although cheaper ones will pulse in color and do some weird things with your image... they also have a bit of a sickly yellowish thing to them.
If you don't have a decent audio setup, they throw a ton of RF interference that will mess up your audio (non-XLR cables are basically giant radio antennas waiting to intercept the spark gap transmission that the fluorescent light uses to glow). Test before you're on set or you'll hate yourself later. They also have a very soft light that cannot be made to be sharper at all, so you're limited to soft light only and have no options.
Lights are hot. everyone on set should just accept that it's a fact... my last shoot, we blasted 7350 watts of light into the frame to get the look we were going for (had to match a shot from a bright summer day on an overcast winter day). 2x2000w lights are really warm. Your actors, if experienced on set, will expect that the lighting will be hot... if not, they're going to learn.
We actually used a craftsman worklight in our green room on "Death Bed" as a heater for the actors as we didn't have access to heat in the disused hospital.
The CFLs are cheap, buy some and test them, if they look good to you, go with it... make sure you record audio with your full setup as well to make sure they play nice together... mine didn't: http://yafiunderground.com/Video/Reel-5.300.mov
That buzzing is full spectrum and can't be removed without killing the actor's dialog. Everything I did here needed to be ADR'd... wasn't, but the on set dialog is unusable... specifically the result of the CFLs we used for all of our lighting in the shoot. This shoot resulted in just shy of $1000 in audio upgrades to prevent the problem.