well honestly ... everyones right i mean, theres no wrong answer, it depends on a lot of things though on which is more effective or useful, if youve got a lot of not so strong shit, joints all the way, you can kick back relax, and if you roll a few in advance you can just go one to another and not have to stop cash ur pipe re pack, and shit. if its better shit itll take less and you can put just the right amount in the bowl and be happy with it,
but on another hand, joints keep burning either way, pipes you usualy have to light ever other hit or so. which is both good and bad,
personally i like both pretty much equally, the only time i smoke is with my girlfriend not all that often, so its just w/e mood hits us, whether we want to pass a pipe around a couple time and get buzzed, or pass a joint, or our own joints or some combonation of all three usualy works out, and before someone asks what kind of weak shit we have, we smoke mostly herbal stuff, its cheaper and takes a lot more to get high high, but thats fine,
so like everyones said, its a personal choice, depending on mood, stash, company, w/e