The Wyndham Garden was a good stop to Park and Fly at Newark. It is a 5-10 shuttle ride to the Air Train P4 station. The rooms were clean and quiet. Small bar and restaurant on premise. Elevators were tiny and a little rickety. I would look to upgrade those as a priority.
The worse part of the stay was getting to the hotel. If you are not familiar with the roads in the area, leave plenty of time to get there. Directions are near impossible, even with Waze. So many quick turnoffs and switchbacks that one can easily miss where to go. Definitely go in daylight so you can see the signs!
Other than that, the Wyndham was great.