I have been using the smart 4 mini now for almost a month as my primary business phone, it has an amazing standby time, its nice and fast for doing work related things, like browsing the web, emails, document or two.
The screen is okay, but you need to view it at an angle, not the end of the world.
BUT, it is let down by the fact that it has a pretty much useless touch screen, its unresponsive , miss types, and sending a sms is a nightmare. and I do believe that if they simply added a proper backing ,it doesn't have to be glass, but a nice think plastic backing, it would be perfect, at the moment it flexes too much causing all sorts of drama on the touch screen.
Hope they fix it on the kicka.