With a pellet grill, my usual method on butts and briskets is to start out at the lowest setting for the first hour or two, then bump up to 275* for the remainder of the cook. The low temp at the start lets the meat get more smoke since pellet grills produce more smoke at lower temps. I've done 225* all the way, too, and didn't really find any benefit in doing so.250-275 is for offsets I believe, pellet smokers are a bit different. Im still a rookie tho so could be wrong