As per my Experience ACT is better than Air tel 4G in Hyderabad.
Previously I was using Air tel but after some time speed was decrease and when I have contact to customer care then simply they have answer some time 4G signals not coming to your area. After doing so many calls I have switched to ACT broadband and till now it is working quite good.Even I have switch all my air-tel numbers to Vodafone.
So I will recommends to people use ACT for best service, speed, connection reliability and support.
Regards
Sachin Kumar