I have TATA docomo photon plus as well as had their prepaid mobile connections too. Photon plus is good (In Hyderabad n Vizag n most of the time in the train from Hyd to Vizag too). Their customer service is very prompt. They keep their promises.
Mobile services was also good until I realized that that offer I was given was only valid for 3 months... then I had pay higher prices... so I moved on, but I would say its customer service was still better than Reliance, Airtel with whom I had my connection before and now...