You will be fine at that hour. There should be plenty of seats. I've never had a problem. You can see how safe and comfortable the ride is with a few passengers laughing and randomly talking. That's normally how it is. I would not hesitate to book Newark if the price is right.
I went back and followed that video a little more. It's so boring since they get on at Metropark with a 45 minute ride into NY. zzzzzzzzzzzzzzzzz
(It was a Sat around 5:30pm that day).
You can barely see the double seats facing one another at the very front on both sides which appear to be open. (they are the last to be taken usually)
Finally around the 22:18 mark they arrive at the Newark airport station. I was surprised to see so many people on the platform with luggage all congregating together. It's usually not that crowded. You'll hear the conductor come over the intercom announcing there will be another train in 7 mins. that's probably because most of that group were all trying to board between the same 2 cars and got stuck waiting for people to move. Passengers are allowed to stand and ride in that nice wide open area you enter between the cars when you first board. (seen in the first few minutes of the video when he/she first walks on before turning right or left to enter one of the cars - they bear right)
So it's not uncommon for people with wheeled luggage to just get on and stand right there by the doors and not move any further.
Notice how nobody from the airport station seems to board the car in the video. (you can hear the doors open but there's no activity) That's mainly because this was an 8 car train being filmed from one of the front cars. The front cars of the train are usually the least crowded. Most people tend to board the middle of the train. So you can safely move away from the pack a little to board the next section of cars - around where you see the group start to thin out significantly in the video at the 22:56 mark.
Watch it again at the 30:00 mark and you'll clearly see what the seating looks like and storage rack above plus how empty it is at the "Newark Penn Station" in NJ. keep watching a little bit further and they'll get up and walk the length of two cars. you can see the passengers with luggage congregating in the front section of the 2nd car as he passes. Their bags are between those two benches that face one another.
Sorry to go on and on and I don't want to confuse too much. Hopefully, a newbie won't shy away from this if EWR is the cheapest option. This train really is a convenient, quick, safe, low cost, reliable way to get into NYC from there.
