I tend to try and keep things pretty simple. e-prime for me is just anothert tool in the kit to use when it suits or serves some purpose to me. I tend to agree along the lines of Rat and Rza, more than anything it is a way to cross-check my own thinking.
When I start getting worked up about something, when those intense feelings start to rise in discussions and debates, that to me is trigger to start applying some simple concepts of e-prime to make sure I'm not rolling down the slippery slope. The basis to me is to start eliminating the word "is" in my own thoughts, if not so much in what I'm actually saying. To me it simply helps keep some objective oversite.