I've never had any accuracy problems using this technique, the only time I find a problem w/it is if I have to do a lot of string skips or a broken arpeggio, then I'll resort to my wrist. As far as endurance its the s@#$, listen to any be-bop player who uses this technique like Jimmy Bruno, Barney Kessel, or Pat Martino....if your going to take a 5 min solo playing straight 16th notes it's the way to go.
Aiwass...if you had the problems you were describing it's because you were tensing up while you were playing. You hands and arms must remain totally relaxed for this technique to work, which is why I guess a lot of heavy metal players don't use this technique.
[Edited by chris mood on 06-13-2003 at 01:54 PM]