I've been several times. Best music fest there is imo, but since they joined with AEG it is essentially two festivals in one: a general popular music festival with big name acts as headliners (e.g., this year Elton John, The Who, Pitbull, No Doubt, Hozier, etc.); and a culture and heritage festival filled with great regional acts.
There are ten stages with music going continuously from 11-7, including a Jazz Tent featuring exclusively jazz musicians, and Economy Hall, featuring exclusively trad jazz.
Plenty of places to find live jazz at night, every night, too. But also plenty of jambands, blues, funk, rock and various genre-bending forms of music. Bottom line: something for everyone, no matter what your musical taste(s).