Airtel is the best when it comes to SD channel. They have so much great SD quality. Airtel customers don't even want HD variant. Nor would Airtel give them. That's why they are settled with channels like MTV and Vh1 channels over MTV HD and Vh1 HD since last 6 years. Tata Play is plain bad. That's why they got more HD channels over SD channels.
Audio/Video quality of SD/ HD channels as well on features, functionality and overall user experience basis Airtel XStream Box is lot better than Tata Play Binge STB.
Only advantage where in Tata Play Binge Box scores over Airtel XStream is that they provide some hours of cloud recording free but that is not of major concern. They may start charging soon for this basic cloud recording pack too just like they have now revised the pricing of Binge OTT plans and made it expensive specially for those wanting to watch content on their Binge Box / Fire Stick/ Smart TV as such plans start from Rs. 249