I think Apollo Brown is 1 of the best to.
That guy makes Boom-Bap on the level of DJ Premier and Large Professor i think.
Although i do think Dilla and Ye are better from a technical standpoint cause i personally would think those beats are harder to make with the elements they add themselves.
I think Apollo Brown has the best soundquality. His mixes sound superclear although i personally would lower the vinylcrackle in the mixes a bit. but that's just me.