Other than limited bandwidth from the ISP the park uses, one of the biggest hinderances to a good wifi experience is the power of the transmitter in your internet device. It has been known for some time that the device makers (and Apple is the leader and undisputed champion of this trend) are de-powering the radio transmitters in their devices to increase battery life. The result is you may see the signal fine, but the wimpy radio in your I-pad doesn't have the power to make the two way communication necessary to have an internet session. It is the digital world equivalent of walkie talkies where one party can hear just fine and the other party gets nothing but static. Add to that the fact that the wifi access point might be hundreds of feet away, with a couple of all aluminum RVs between you and it, making a clean wifi connection with the requisite two way communication becomes problematic. To the original question, no resource exists that would accurately rate the wifi or cellular service at any particular park. The preceived reliability would depend on too many variables including what you need to have available when the call comes in. If it is to just notify you that you have to go to the jobsite, you will probably be OK. If you need to log on and remotely take control of the NSA's supercomputer network to stop a imminent nuclear attack, you probably should consider plans that do not include using RV parks' wifi.
