I've only used it with the octave up so can't report on the low setting but it's been pretty quick. I haven't used a ton of different octavers so can't compare to every one out there -- it's definitely better and quicker than a Zoom B1/B2. I'm not sure how to describe in technical terms but I don't have to consciously 'be early' in order to make everything sound tight. With long sustained notes there can be a kind of 'warbling' as they decay, adding a touch of chorus smooths that out.