Yeah, I know of lots of MITM sites but a) most of them have not been updated in a long time and b) some of them are really crappy. And of the sites that have forums, the majority of the posts are not even related to MITM and those that are are pointless crap. A lot of threads I've seen at the FOX forums for example, are repetition of questions that have already been asked literally fifty million times.
At least here at the MITMVC, our off-topic discussions are actually sensible and worthwhile topics.