Location probably plays a role. There are very few trails around me that a single locked, 33" tire truck with a decent driver couldn't finish pretty easily. Most of the hard stuff is optional. Even a lot of the big moab trails like Metal Masher or Kane Creek are like that. So a lot of guys who are underbuilt never really have issues on our runs.
It really is a toss up. Although I've seen first hand what 33s and atrac will do so....
Should have seen what 32s and atrac did for a couple years. Atrac just isn't capable for slow speed rock crawling maneuvering. It really relies on a certain amount of speed and rpms to work effectively, at least on the 4th gen platform. It could get me up a 3 foot waterfall, but it couldn't get me through an off camber slot canyon that required finesse to stay off the canyon wall.