No, I haven't learned Chen style tai chi. What I was taught is Yang style. Though I do have a number of books on tai chi and some of them do show Chen style forms. I could look up more about the history in these books, but as I recall, they do believe that Chen style was the first one which makes it closer to the hard, external styles than others. There are explosive movements and the martial applications or moves are often more apparent. I think our MA teacher did say that he knew Chen style tai chi, but he never taught it to us. We only did the Yang style long form. I'm more interested in tai chi than kung fu though so perhaps one day I'll get around to learning some other forms and styles.
Hopefully not too much of an aside, but the 24 posture form mentioned is a standardized, simplified form which I believe is based on the Yang style form. IIRC, this was something China did and backed in an attempt to improve the health of the general population -- here's a short, quick, simple tai chi form that you can practice to stay in good health. There's also a 48 posture form and a 42 posture competition form, both of which I think are based in Yang but incorporate moves from other styles. And four styles of tai chi have their own competition forms as well (I have a book with them). About the only exposure I have to Chen style tai chi is through the few moves from it that got included in the 48 posture form. I learned it a while back using books and video tapes, but since I learned the long Yang form for real, I've basically forgotten the few other simpler forms I tried teaching myself. Not necessarily a bad thing. But I might have a better background now for relearning them if I really wanted to. Something that did look interesting to me was a Compact Tai Chi form, I think in a book by that title, that tends to coil and circle the standard linear movements so that you can do the form in a smaller space. It's also one of these combined forms, based in Yang but taking moves and aspects of other major styles as well. I never got very far with it, but I have the book for reference if I want to try to pick it up at some point.
