<p>There are no differences, really...Units 1 and 3 are both one block off campus; Unit 2 is 3 blocks off campus. Units 1 and 2 share the Crossroads DC that's in the block between them; Unit 3 has its own DC. Units 1 and 2 have stuff like workout rooms, some quiet study rooms, etc, but Unit 3 has that too, I think...and all the units have their own Residential Computing center. There's really no difference.</p>