The only time I ever encountered Laser in NJ was about maybe three years ago on RT 42 at the approach to the Walt Whitman Bridge. I think that it was Port Authority doing an evaluation. Never encountered Laser again.
Laser is alive and well in NJ. I have seen it infrequently in local towns, however, it is heavily employed by the NJSP on highways such as 80, 287, GSP and the Turnpike. Running into NJ laser is so random that I can't give you a recommendation as to whether parking sensors would be of value.