Single, Double - Why not Both?

Are the multilevels compatible with the single level comet coaches for regular passenger service? I've seen both of them together in equipment moves, and other commuter railroads do this such as MARC and MBTA, who uses similar equipment for their trains as well.

I think yes but it's better for NJT to keep the double deckers in one consist and single levels in another.

The Door comm trainlines of the MLV's and Comets are not quite compatible,so mixed consists are not a bright idea.
MBTA ,MARC,And UTA's Frontrunner don't have that problem.

Mixing the coaches nullifies the PEI as well as the trainline computer.