+1.
It may not be true with all groups, but I find that point buy often encourages min-maxing. Since I usually have one or two players who optimize, and three or four who have probably never heard the phrase "optimized build" associated with gaming, anything that encourages min-maxing just throws off the dynamic.
Edit: Because anything that encourages min-maxing increases power disparity when only one or two players optimize. Thought I should clarify.