Hi Andy! I am the publisher of a great book on the Maharishi Effect, which you would enjoy: An Antidote to Violence.
As the publisher, I can say that while the peer-reviewed and published research stacks up, it has one critical flaw: it is all conducted by researchers who are themselves members of the TM movement. So, unconscious biases cannot be ruled out.
The book, speaks for the TM leadership makes the provocative offer to provide a large group of TM meditators to any credible, non-affiliated researchers who wish to replicate the experiment.
I hope someone takes them up on the offer.