I like my 2 very much, it's very comfortable to hold and easy to carry in pocket bcoz of its small compact size. From last 4-5 months usage as a primary device to connect internet(I disconnected broadband very next day of purchase of jioFi) I have not faced any issue with it.
And regarding Wifi coverage, I keep it at 3rd floor to get best tower and its Wifi reaches upto 1st floor (around -85 to - 80 dbm directly below). To cover whole my home i.e. ground floor I use my broadband router as repeater.