One bottleneck I seem to have in scales is the turnaround at the top, at least with certain scales/passages/fingerings. For example, Bernhard's speedy alternative fingering for G in the left hand: 321 321 4321 321 43 - at the top of this 2 octave scale one plays 434 (f# g f#) and that slows me down a lot. Is the answer just time and practice?