I own both the X-T1 and the X-T2 .Both are great cameras,but....the jump considering the image quality between the two sensors ,the old one and the new one, is the biggest among any other new cameras released in the market (at least the last 3 years) .The AF-C might have limitations in raw buffer ,but it's the best in terms of AF accuracy and jpegs are ok for me.When i shot 11fps burst on fast moving subjects ,i get like 75% super accurate images ,zoomed all the way . In terms of low light ,X-T2 is at least one stop better than the previous generation and the noise is ok up to 12800 ,while on the X-T1 the limit is 6400 and not many keepers (waxy skins etc).
For portraits the joystick is useful and makes your life easier,maybe not the fastest ,but would x-t2 or x-pro2 be the same cameras without it?i guess not.