I switched over to ACT from Airtel about an year back. Airtel’s broadband did work fine. However errors in billing and their reluctance to correct the errors made me switch over. Also ACT provided better speed for the price.
ACT has an office right in the apartment complex I stay in(which is probably a reason for the better service I received compared to the other reviewers here). Speed has never been a problem and the engineers have been quick to attend to complaints. I had a bad experience in the beginning on connection reliability. Three service engineers tried to solve the issue and failed. The problem was rectified later by another service engineer. The connection has given minimal problems after that. However, it should be noted that most of the engineers are bad except for a couple(which I believe is an issue with most of the service providers).
Billing has been accurate, which is pleasant considering the horrific experience I had with Airtel earlier.