Well I happen to love documentaries as a genre as a whole, but I cannot say that I have seen one on Muay Thai, or even heard of one for that matter. I am glad to see that there are some links above and ways to go and find some, so thank you to those users who posted those. I am hoping that there is a full length, more professional quality one out there but maybe I am aiming too high. It should be interesting to watch, though.
Yes, I'm watching some. Although I have started watching them a short time ago, I can already say that I have learned a lot and I am increasingly interested in watching more documentaries. The most interesting thing I find in these documentaries are the kinds of approaches that are made about the subject.