I can only tell you what we see. And what we see when we film people is that slow playing doesn’t look like fast playing. The differences vary depending on the joints involved, and they type of motion that joint is creating.
When I filmed musical examples for our Volcano seminar, I used a forearm-wrist technique. We did them at medium and fast speeds, and the medium speeds look very different. The motion path for the medium speed clips follows a more vertical angled trajectory, while the faster clips are closer to parallel with the strings. The slower playing also has pauses in it, where the pick comes to almost a complete stop after each pickstroke and waits before playing the next one. In the faster clips, the pick almost never stops moving.
Players like Andy Wood, Molly Tuttle, and David Grier are double escape players, mostly with wrist motion. When they play slower, they also experience the velocity change, where the pick waits or slows down between pickstrokes. The shape of the motion path also becomes more vertical, like in my Volcano examples. However with double escape this makes the motion look more like stringhopping. The slow technique of these players is probably not the same level of efficiency as their faster playing.
It is very difficult to try to simulate fast motions when playing slowly. It is difficult to move very slowly with continuous motion, and it’s very difficult to use motions with very shallow escape that just barely clear the strings. That kind of playing is much easier to do when playing fast.
To learn to do fast technique, you have to play fast.
