M2..

Last week I bought Mike Robertson and Eric Cressey's "Magnificent Mobility" DVD. When I was playing competitive rugby at a fairly high level (a high level for an American that is) Dynamic Flexibility and warm-ups trickled down from the national team, but for the most part they were used incorrectly. As such, when I bought this DVD I was not unfamiliar with the concepts behind dynamic mobility, however, some of the focal points I was taught were well and truly wrong. Magnificent Mobility did a great job of filling in the gaps.
The DVD itself, is pretty well done, the music is horrible, but you can see, hear, and understand all of the information as it's presented. Mike and Eric do a good job of explaining the reasons, and uses of the movements, and an excellent job of actually teaching the movements themselves.
As an athlete with some fairly significant mobility issues, this DVD addresses my issues: tight hips, hyper-mobile lumbar spine, tight hamstrings. I have used movements from M2 before my last 2 rowing practices, and I have felt longer and more relaxed in the boat. Results in the long term will have to wait for the long term.
The only criticism I have (music aside) is that it would have been helpful to have an insert, or section of common ailments, and progressions to remedy them, but the product itself is not lacking as much as it would be nice to have this added feature.
In summation, any athlete or coach that doesn't already have a strong working knowledge of dynamic flexibility (and if you have to think about that answer, the answer is "you don't") needs this DVD. I know this is a strong statement, but I firmly believe that after 12 years of rugby and 3 years of rowing, mobility (or problems associated with a lack there of) has held me back more than anything else. So far this has been money well spent.