Airtel Prepaid Bangalore Plans


I'm right now using AIRTEL freedom plan 1.2p/s A-A/O and 1.5p/s A-LL ; first 2 sms/day are charged @ 50ps and then 300 sms free for that day.

The plan is available on Airtel site: Prepaid Tariff-Prepaid Mobile Plans-Prepaid Service in India : Airtel

Now I want to know if there are any other more economical plans for Airtel prepaid users in Bangalore as 1.2p/s = 72 p/min
Or are there any other operators with the similar coverage and cheaper plans?

And another thing I want to know is that whenever i call someone, the call duration counter on my android phone shows some 'x' seconds but when i receive the balance infor after the call, the call duration is generally more that what the duration on my phone is. Is this the same across operators?