I've heard Petrucci, Richardson, and Vai all explicitly mention the amount of effort it requires to get to the level of polish they achieve in their live playing, and how much continual effort it takes to maintain a particular fast passage at the correct tempo. I have been working at some fast music for a while, which has pushed me to new levels of control, relaxation, and speed. I started very slow, and over the past year can play the faster sections perfectly with control and good tone (even matching vibrato), staying relaxed up to 85% or so speed. Sometimes 90. But I think I've spent more time trying to nail this last 10% then I have getting it up to 90. When I play full speed I find I can either be precise OR relaxed but not both at this tempo, which introduces slop in one direction or another. I'm writing to find out what it takes to get that last 10% of speed and control in fast music. Please share your attempts, failures and successes to achieve that last 10% of speed and articulation. Anyone can play controlled with good tone if you slow it down enough, but what does it actually take to get that level of speed with articulation? What worked for you? How long did it take you to get that last 10%? Was it worth the payout? Is it enough for you personally to be mostly clean with some slop, or does your slop haunt you at night?