The Air Zone is quite interesting among DiMarzio's pickup line. While many are very focused on metal and heavy gain and have a very difficult-to-dial-out mud in the midrange, this pickup is actually very open sounding and quite classic in its tone.
Cleans are improved by the 'airbucker' technology and have quite a rich, woody and middy sound. Gains are more vintage sounding than other Dimarzio units and excel for classic 70s and 80s rock tones. Add an overdrive pedal or Tubescreamer type and this pickup sings; its smooth midrange comes to life with some bluesy playing or rock histrionics.
Overall, a good and versatile pickup; what stops it getting five stars is that it's more of a utility pickup rather than one with its own particular character - match it up with a bright guitar and it'll smooth it out beautifully, but it lacks the identity of a Seymour Duncan Jb, EMG 85 or even DiMarzio's own Suoer Distortion...however, that may be exactly what you're looking for to complement a guitar's natural tone and character.