| The School of Agility is exactly what it's subtitle says A Technical bass method of a scale system. Starting with e major/e minor he lays out at least 8-10 fingering for each major and minor scale as well as one cycle of arpeggios, one fingering each of minor maroj, IV6, diminished, etc.
The fingerings are very useful and practical, as I can find a scale to demonstrate a fingering for any playing situation. As opposed to Rabbath, Levinson uses 1-3-4 to strech over a whole step-half step minor third and 1-1-4 for half-whole.
I wouldn't say it's better than any other scale book, but not any "worse". If you want to study with him, that's a diffrent story. | 
