I presume you mean just the NW area of NJ based on those counties, but for what it’s worth, Mercer county is pretty great once you you get away from Trenton.

My wife and I live in Hopewell, NE of Trenton, W of Princeton and it’s a very nice area. Safe, quiet, not quite as expensive as some areas up north, but a little pricer then some of the more rural areas of the state. You’re pretty much in the center of the state so it’s only about 55 mins to NYC, 45 to Philadelphia, 45 to the shore given the proximity of major interstates like TP, 195, and 295.

Its also has some decent nature stuff in the area between the Sourlands and places in and around Princeton. Some good restaurants in Hopewell and Princeton area too, some cultural stuff is to be had in Princeton as well.

The taxes are moderate for NJ, again lower than what one would expect to pay in NE counties, but definitely a little higher than some Southern ones, but we can’t complain too much, my wife is a public special Ed. school teacher, and I work for both Princeton Univ, and the US Dept. of Energy at the National Lab.