Haven't seen a poll in a while.
What's most important (Can't say all, we know that, what's MOST important).
Speed
Spin (movement)
Spot (Location)…
D...all the above
Most important? Good form. With good form, speed is a natural byproduct. Control comes from practicing good form. Once you can demonstrate proficiency with good form, start working on drop spin. Add a change. Begin to understand and play with the rise next. Then, spend the next 4+ years mastering the three.