I went to the fall and spring swap meets at E town religiously for 30 years until I moved out of NJ 5 years ago. If you haven't been there in 25 years and are expecting it to be like it was 25 years ago, you will be disappointed. It is not like it was 25 years ago, but then then again what is? There are a lot more professional vendors and a lot less average Joe's clearing out their garages and selling their extra parts, etc.
But, with that being said, if I was still in NJ I would definitely go because I usually found something interesting to look at or buy. I still miss going to the E town swap meet and havent found anything similar in my area.
So, if you've got the time and feel like spending a day walking around outside hoping to find your needle in a haystack, it's worth going, just don't expect it to be like it was last time you were there.
That's my .02