I have been using BSNL BroadBand for about 18 months.In my locality I don’t have any other choice other than BSNL.My connection used to be unreliable (A year back)..Now it is sort of OK.I can’t afford to have even 10 second downtime in internet.Reliability is big big concern for me.
I bought 2 DataOne connection from BSNL and combined that.As this increases connection reliability.(I also have TATA Inidcam & BSNL dialup for backup)My brother has been using Airtel Broadband. He says it is excellent.He doesn’t have disconnect once in a while.
I once tested the speed at his place.Speed was as good as BSNL.My suggestion to you is:If what you are doing in Internet is just browsing and Downloads, it shouldn’t mattermuch whether you select Airtel or BSNL.Interms of connection reliability Airtel might be little better.In case you didn’t know already, Stay away from any kind of Internet offered by Reliance.