I use vodafone and its awesome network, still it has some issues.
Its network coverage is fine unless we enter a town or village. I have faced some issues in its network coverage while being in some villages in North India. I had a terrible experience there -
I couldn’t access the Internet due to bad network coverage. There was no 3G network and 2G was giving speed about 2-3 KBPS, hardly able to even perform a Google search.
The roaming charges were high. It costs a lot to send a sms or make a phone while roaming.
Also faced bad quality calls and call drops as well, a few times.
But It works just fine when we are in a city or somewhere It has good network coverage.