Avoid airtel DTH if you do not have patience to deal with lousy customer service.
Every time you call wait time is minimum 6 min and that too it will disconnect after that. If you are successful in logging a complaint one cannot be sure if engineer will visit. BTW airtel have a facility to escalate your call to nodal center who are equally lousy.
They also are very late compare to competitors in adding new channels, Ex: For very long airtel had only 1 HD channels.
But telecast and set top feature wise Airtel is very good . I have experienced Tata Sky.