Roughly speaking, I think in terms of:
<35 = less than replacement level
~40 = replacement level
~50 = mediocre
~60 = good
~70 = excellent
~80 = elite
I try to think in terms of abilities rather than single attributes. So a guard with about 80 in speed, perimeter, and ball-handling will be a lower-end-of-elite perimeter scorer in D3. Likewise, a big man with about 80 in athleticism and rebounding will be a lower-end-of-elite rebounder. I move it up about 10 points for each division.