In Delhi.... in my personal experience I did not find anything better than Vodafone..... MTS was good but has also deteriorated now..... I mean all congested places you could find network...... and Jio....... extremely poor network or no network.... and on top of it either you buy a new phone or haggle with poor JIO4GVoice app...... and then the interconnection issue.... and no person in his right frame of mind will make Jio as his primary business number......1000 times better network? ahem ahem.
I think vodafone would be my last choice out of big 4.