After a while, in "complicated" music, such as Jazz, you tend to go much more towards arpeggios than scales, since arpeggios have all the important "target" notes of the Harmonic sequence you are soloing over... So you sound much more melodic that way.
Also, Arpeggios, due to their structures, are usually played in one note per string sequences, which allows to play them by "sweep picking" the strings, hence going WAY fast and sounding totally HOT... :)