I am a big fan of tillamook, but it has not made it onto any of my pizzas. I reserve it for dishes that do not involve melting. Not becuase I have found it inferior, but because we enjoy the perfectly aged cheese so much as it is.
I have kept my eye out for mozzarella from Tillmook for use on pizza, but alas, I have not come upon any. I also have not seen food service sizes in my area, wholesale or retail. (I could have sworn I used to be able to find them many moons ago.) I can't afford to purchase a case of the smaller blocks on a retail level. So again, tillamook is reserved for unmelted dishes and appetizers.
Thanks for mentioning Brandon cheese, I have tried it on a few occassion and throught it was similar. I did not find it the same, but the closest to the tillamook label. Brandon usually costs a bit less too.