i don't think studs are necessary here in NJ, and keeping them on year-long, i think they would hinder you not help (especially with weight). i've ridden through a few winters now, encountering straight up water-ice (not like snow-ish/crusty ice, if you know what i mean) on just knobby tires for a few winters now (including rides at chimney rock) and i have never really had a problem.
if you've ever ridden the sourlands in the winter, the boardwalk sections can become a nightmare - as in totally sometimes covered in 1/2" of ice for the entire length of the boardwalks. i have yet to totally blow it when the boardwalks are in that condition with just normal knobbies, you just have to ride extra careful, but you can clear most anything. if you are on a climb and you hit some ice, that is a different story, but i don't any areas in NJ where the trail becomes an icefall completely for over a 20/30 feet at most. just dismount and walk up... part of the deal of winter riding.