Thanks Faeleia!
dash: a word used extensively by pointed pen masters of ornamental penmanship in the late 19th and early 20th centuries to mean energetic, spirited, spontaneity, liveliness, and snap. Root word of dashing: meaning elegant, chic, dazzling, or stylish in appearance and manner.
Yes, it is difficult to have control and speed. It really takes developing the muscles in the arm and shoulder.
Lori - Yes, I definitely have to go fast or I get shaky lines. However, there has to be some control, too. This is why good, sturdy, but flexible nibs are desired. If you go too fast or if the nib catches - splat! It is also why you need to study the flourishes so your brain knows ahead of time where to go.