Don't know which is better, I spose it's a matter of taste. I have seen it done both ways also. I have also seen bathfitters jobs, that's where a company comes in and puts an acrylic liner over your existing tub. They will ask the customer, "Do you want the matching surround to go to the ceiling?" The jobs I have seen all the way up looked great. You can alway's stop your tile run before you get that far, and do a dry run to see how it looks. I spose if you stopped short of the ceiling, then some kind of semi-gloss paint would also work. Good luck.