I definitely think TM drivers are the longest drivers.
MWT also helps a bit.
People always think money has a lot to do with what the players use but if you ask any pro, they'll tell you that once you get to their level of playing and with how much money they make on tour, its not about money. The worst player with a PGA tour card is a millionaire. Seriously, would you use a taylormade driver to get paid $1 million a year and give up winning one of the majors because you have a sorry driver in your bag?
I dont think so. Especially if you're as passionate about the game as they are.