Dynamics cannot even come close to the speed of electrostatics by definition. Some dynamics fake sounding very fast by shoving the treble way forward, but in terms of actual speed, not even the Qualia 010, which is the fastest dynamic around by miles, can compare to electrostats.
The question though isn't of being the fastest, but of being fast enough, and in that regard, it depends a lot on your music. If you listen to smooth jazz then I really doubt speed matters all that much, nor will the difference in speed be as readily apparent as when you listen to death metal, or to full-size orchestral music, or extremely complex electronica like Shpongle. You really have to stress a driver in order for its true abilities to become apparent, and when you do this, you will very quickly see (most) dynamics falling behind the music, while electrostats just take everything you shove at them and ask for more.
You pay for that speed with less driver excursion, but then you can't have it all, not even at the top of the food chain. In headphones, anyway.
If you want a fast dynamic, get the Qualia 010. The K1000 is pretty fast too, and to be honest, a balanced HD650 is pretty damn fast too, at least much faster than it is in a single-ended rig. On the other hand, when it's underdriven it's one of the slowest headphones around.
The TakeT piezo driver does have an amazing combination of speed and impact, but the headphone still needs some work before it's ready for prime time (at least a dedicated amp a-la-Stax that can drive it right).
Balanced armatures also have a good combination of speed and impact, but they fail at treble extension, which hurts their ability to replicate transients.
