I would actually wait for Paytm. Airtel mobile apps are crap. My primary purpose would be to get access to a better banking app. Yes Bank recently overhauled their mobile app and the new app is another crapfest.
Paytm has temporarily withdrawn their payments bank application if the rumor is to be believed. Few very reliable Twitter accounts are saying so.
Paytm and others may have the capability to churn out apps with nice UI. But they lack in everything else. My bet for the best payments bank in India is on India Post. Their capabilities are endless. If they know how to utilize it properly. India's (or world's ?) largest banking + logistics network, insurances, added services, physical presence for rural population and lot of capital. They have everything. Only thing pending is their own ecommerce portal.
Wait for the full-scale rollout of their new software infrastructure. Will be done in 2017. One can not really run virtual banks. Rural people flock Post Offices almost everyday. They will blindly open account with IPPB as its govt bank. Airtel can forget getting customers in rural regions. Rural people do not trust their cellular service due to their backdoor balance deductions for prepaid customers. I don't think they will trust Airtel for keeping deposits.
I know its not easy to loot bank clients like they do for their cellular subscribers. But rural people will not understand it. Airtel is a chor company in their mind and any product associated with Airtel will remain as chor only.
with 1 lakh rupee limit, these payment banks are not really an option for well someone like me. but it is still a good option for a backup account. deposit extra funds. benefit from high interest rate. use it for wallet transactions.