Jio connectivity and speeds in my home region are excellent. The company is employing Small Cell Unit technology as opposed to traditional cell towers (BTS) for better connectivity in high-rise societies. While Airtel only spends crores on marketing. It is a technological fact that traditional cell towers cannot provide same level distant connectivity over 4G howsoever you upgrade them. 4G needs close user proximity and that is possible efficiently with Small Cell Units.
That being said, I hope Jio addresses the issues with International roaming. It is the only reason I am reluctant to port my primary number.