Improves the aerodynamics somewhat. Although, a brick is still a brick.
See, I'm not sure about that. Seems like this was debated pretty thoroughly in months or years past, probably over on another forum, with no real hard data to back up the assertions. And, even if some slight rake provides an aerodynamic benefit, 1.5" from front of slider to back of slider seems, intuitively at least to me, to be a lot. That said, I'm going to measure those points when I get home and see what mine is (although I suspect it's not that much, if not fully level, because my rear leafs are sagging a bit)
In any case, like I said not sure stink buggin' provides any real benefit. Scientists? Engineers?