^IME, I'd say try Philly over NJ all day...I'm not an expert on New Jersey, but I've been fucked with and questioned a few times there not even doing anything dope related....I'm sure every city is a little different, but if you don't know exactly what the fuck you're doing, you could be in for trouble...
Philly, as I know it....It can be hot, and if you're in the wrong place at the wrong time bad things could happen, but 9/10 times the cops won't even bother with you even if they know you're a user...It's futile and they realize it...