the books are good enough to bet in NJ. Sometimes the lines are better than offshore but most of the time they are not. Offshore has the openers 99% of the time. A combination of legal and offshore is the best of both worlds.
hard to say what type of bettors are in NJ.. I would say after 1 year of betting NJ probably has run into some bettors that are hard to beat .
Nevada handle is still about +1.5 billion to +1.9 per year more than NJ by time sept rolls around. I would think California/Az bettors have a bigger handle than NY coming over state lines. Also nobody flies to NJ to play compared to flying to Vegas. Revisit in 5 years.