I am using MTNL wifi since last 3-4 months..

Till now, I have not faced even a single issue .

Net speed does not fluctuate... no disconnection.

Charges are reasonable .

So, thumbs up to MTNL . If you want to switch your internet service provider, you can think of MTNL.. (only thing is it takes a week for new connection..so just have some patience)

Earlier I was using TIKONA net and the experience is horrible ( Sending bills even after disconnection ..LOL)