Hi,
I am using Airtel 4G since past 8 months and seldom had issues. I used to stay earlier in Medahalli (Rifco Shantiniketan Layout, Bangalore) and due to poor 3g connections (of Airtel which usually drops to 2G) I took chance and switch to 4G. Amazingly I found it to be good. At the least it drops to 3G WCDMA but never 2G.
Recently I shifted to Kodegehalli (Kadogodi Post) and here I am getting better signal and speed. Though I do not like the proce of hardware as now I want wireless router which they say will cost me 5K as I am not taking new connection, but I do like the speed.