I just finished the 8 week CEPA program I wrote about earlier. The certificate of completion is sitting on my desk in front of me now. I'm normally not that sentimental about stuff but looking at that certificate actually puts a little smile on my face. Partly, it's knowing that I was doing something that may help me, my family, and neighbors, but I guess I also smile because I genuinely enjoyed going through the course and enjoyed meeting the other people every week. We had all ages, from teenagers to folks in their golden years, various knowledge levels from could-teach-this-course to never-thought-of-preparedness-before types. I think there's something of value in it for everyone.
So, going back to the original question of whether CERT (or CEPA) training is worth attending, I would definitely say, "Yes".