I think, all the above posts must be from with either reliance or tata docomo. These all seems to be fake.
I have been using AIrtel 4g From last 1 year, and have never faced such issues like speed drop or a bad service.
Even when I purchase airtel 4g, their representatives called me and asked me for all the details like where will I use, where will I travel etc etc.
They already cleared all the facts and even though, I am getting more than what they committed for.
Now, look at Tata docomo. I was using this prior to Airtel 4g. And Tata docomo harrased me alot, and I have filed a case against then in Consumer courts.