FWIW I have no splash back and just 4 or so inches of upstand, 4 years in and it still doesn't need a repaint, maybe I just don't use the back hobs much?
No splashback here either, but 10cm upstand, and latex wall paint.
The paint needs a wipe down now and then but no problem.
Mind you I am an architect so aesthetics > functionality
FWIW I have no splash back and just 4 or so inches of upstand, 4 years in and it still doesn't need a repaint, maybe I just don't use the back hobs much?