I was about half-way through the process for a competition about 12 years ago.  I had to quit due to training for a new job.  For me it was a real eye opener for how lousy I was really eating.  And as tough as the diet was, seeing the results made dieting easier.  It is something I'd like to do again.  Right now my goal is to due a competition when I am 40.  That will give me a couple years to really get my body in order.  

Loren, a friend of mine that did compete gave me the same advice as far as the weight fluctuation.  He told me that if you should not have to diet for more than 12 weeks.  That is the guideline I am going to use if I decide to do it.

It is very time consuming though.  If I wasn't at the gym, I was either cooking, eating, or cleaning up from the two.  But it is still something that I would like to do.  I want to do one thing that is entirely on me, and not have to rely on someone else(ie. a team sport).