I looked into Liberty RV Park last October but we did not go there.
It is convenient to the city and public transportation (train/ferry). The park is essentially a parking lot with very tight spaces between rigs and all gravel.
There is an on-site bar that plays music (loud) until 2:30 AM on the weekends. They make a point to note this on their web site so I suspect they get many complaints about this.
Others have reported it is not very clean
http://www.njcampinginfo.com/liberty...rk-review.html but I have no first hand knowledge.
Price is up there but there is little else to chose from in the area. We considered other parks farther south in NJ but in the end we just drove the car there and stayed with relatives rather than taking the rig.
There are many reviews available. Just google Libery RV Park NJ.
Hope this helps.