I am using Airtel broadband from last 2 years and its a very nice in terms of connectivity and speed, I use 4 Mbps plan and it gives without buffering good quality video speed on Utube or online movie watching website.
In 4 Mbps plan they provide 80 GB high speed quota which is quite sufficient for four people, I also appreciate the customer service and response quality.
One time I faced problem with Airtel broadband connection when I was shifting from Rajendra Nagar to West Patel, I applied for shifting of my Airtel Broadband connection but they refused because they don’t have landline connectivity in West Patel Nagar, Hopefully they will increase their area of connectivity specially in metro city like Delhi.