I literally watch dozens of 1200 codes go at each other same altitude every day, on targets that merge. On a nice VFR weekend day, probably more than that. I'm always amazed that we don't have collisions more often. The area 5 DME around SBJ from 4000 and below is always a dangerous zone, as well as that triangle of airspace in between, and to the north MMU, CDW, and TEB from 2900 a below (below NY class B).