I dont do CF, but a ton of my buds do / have done it, and will tell me the draw of it is the people feeding off each other, the comradery, and mostly people who were previously sedentary, are seeing results quick. Like any other fad thing that has worked in the past, or any successful physical trainer, its the ability tio motivate people, and make them believe they can get results. You take a group of out of shape women, turn them loose in a regular gym, they may see minimal results. Put them in a CF gym, they see much better results and faster, due to the motivation and encouragement to continue.
The downside is the likelihood of injury. having middle aged people who arent well versed in some of the stuff they do (Olympic lifts, jumps, anything with arms overhead) is a wreck waiting to happen. My ortho told me all the CFgyms have generated a steady stream of revenue for them. What I keep hearing from the CF proponents is blaming the lifter with doing something wrong that caused the injury. Plain and simple, some people should just avoid certain exercises, but the energy and adrenaline that comes from that environment contributes to people trying things they have no business doing. About half of the people I know that have done CF have sustained injuries that required some sort of procedure to correct (bicep tears, shoulder injury, ACL etc), and forced them to stop CF.
Also, any of the guys I have seen that look worth a sht (muscular size wise) in CF, got that way before CF, and only used CF as a means to lose some fat. If you have to take your shirt off for someone to know your'e in shape because you otherwise look like a swimmer, no thanks,