NJ one day is whatever you want it to be. There's a marathon, 50K, 12 hour race and 24 hour race. I ran the 24 hour race in hopes of reaching 100 miles. It's a one mile loop course. Don't let the trail series fool you, it's a paved loop. To date, the only ultra I ran on pavement is the double blue ridge marathon which hurt enough, 24 hours on pavement OUCH! Despite my pain, it was a great race. Logistics are so super easy. You can have your crew and cheering sections right there on course with you. The race aid station was awesome. I could put in an order for a hot item and they would have it ready the next time I came around. Bathrooms were also nice indoor ones that were heated which were soooo nice on of course what was probably the coldest day/night of the season. The RD is so super nice and supportive. I received several hugs from him and he even personalized my license plate and wrote my 100 mile PR on it. Being on a small loop for so long I made some new running friends and watched a couple runners bust out US national team qualifiers for the 24 hour world running championships, so cool! So even though the pavement was so friendly to me, I still think it was a great event. I definitely recommend it!!! They also have a 3 day in the spring on the same course which also seems very popular.
check out more details of my personal race here: http://runningmarathonmom.blogspot.com/2016/11/that-time-i-ran-for-day-nj-one-day.html