Man I try to ask a question to simplify things and you guys just take it and run with it! I do understand the argument that if there is movement in the studs and you hang horizontal that there would be less seam exposed to each individual movement. I may end up hanging horizontal since I have at least one wall that I KNOW is not 16 on center because of where we place an interior. I'm guessing most of our walls aren't perfect either as we are novices to this whole construction thing.
I will have to check into the butt boards. Not to hijack my own topic, but do the butt boards get connected to the studs at all or do you just screw the ends of the drywall to it? Seems like there would have to be some structure to it for strength in the wall, but if I knew the answer I wouldn't need all of you!
No the butt boards do not connect to the studs, they go between the studs. And they have their own backing. Go to trim tex.com buttboards and read up on them. And yes I mis-spoke about the amount of taping in this instance because of only being able to use 8' boards. And as far as strength lay a 8' peice of rock flat with a block under each end and it will bow. Stand the sheet up and put a block under each end and even put a weight on top and it won't bow. I really don't know how significant that is but it is there