Informix Fragmentation

I'm planning on using Informix's "fragmentation" feature. However, I'm getting a lot of opposition from some folks that have the "I don't understand how it works therefore it must not work" mentality. I'm sure we know some people like this. So, anyway, I have a couple questions: 1) Anyone having problems using fragmentation? 2) Anyone have a good success story with fragmentation I could use? 3) Does fragmentation have any unforeseen performance problems? I greatly appreciate any replys. Thanks in advance. John Dennis