I'm so glad someone else made the connection between Natural Horsemanship and Classical Dressage. I began riding a sort of American competition dressage and then found a classical dressage trainer. I've been taking classical dressage lessons since 1999. My horse not only moves better but she even looks better. She has the topline of a stallion with a beautiful crested neck and strong back. You can see her belly muscles when she moves because she raises her back so easily now. I think the amazing thing is when we work the sitting working trot now, she's actually smooth, yet moving out more and with more impulsion; whereas she used to be really hard and bumpy.
My horse just thrives in this training. All resistance is gone and she works so hard to get it right. I'm always amazed when she extends or collects her trot just by how I use my seat and nothing else. It's been a real joy. And because she knows my seat as the primary aid now, she really responds to the slightest drop of a seatbone or the push of the seat. That also makes me feel really secure as a rider with a horse that is potentially explosive. Having my seat as the primary aid has really made me feel and be more safe while also being both stronger and quieter in my riding. It's pretty fun when I can get her to trot off without using my leg or canter just by shifting my hips...but we're still working on that.

Of course we always seem to get it when the instructor isn't around.
I always have my eye out for classical dressage clinicians; although, just like with Natural Horsemanship, just because someone says they ride classical dressage or yadda yadda, doesn't mean they really do. You have to observe the clinician/instructor to determine. And you'll notice right away if he's not classical. I'm sure you both have seen what I mean.
The only bad part is that I can't put her western saddle on her anymore because of the sheer distance and amount of leather blocking the communication from the seat aid. She kind of stands there with this, 'where did you go?' body language.