Thank you all for your input about the quiet car! Some further research on the Amtrak website led me to this blurb which piqued my interest more than ever:
"Need a quiet space to work or unwind? Quiet Cars are available on many corridor and short-distance trains. Guests are asked to limit conversation and speak in subdued tones. Phone calls are not allowed and all portable electronic devices must be used with headphones (passengers using headphones must keep the volume low enough so that the audio cannot be heard by other passengers). Low overhead lighting creates a restful atmosphere for all passengers, but reading lights are available."
My hubby and I just completed our round trip jaunt to NYC and this was our experience on the train:
We boarded the outgoing leg at our home station with about a dozen other travelers and the two of us immediately walked forward through the cars to reach the front of the train. I got excited when we approached the door in the last vestibule - through the glass I could see what appeared to be a completely empty car ahead with the overhead lighting turned down low. I assumed it must be the Quiet Car, but was puzzled because the door was clearly latched in a way that was not meant for entry. No signage anywhere to clarify the status of that car.
Before I even turned around, the conductor called out to us from the other end of the car behind us, "Hey! Where do you think you're going? There's a bunch of empty seats right here!" My dear hubby spoke up on my behalf, "She heard there was a quiet car." The conductor shot back with an impatient I-shouldn't-have-to-explain-this tone of voice, "That's not until New Haven." He began checking tickets for the other passengers already seated while we chose our own seats.
I was pleased to find that this car was plenty quiet enough even though it wasn't officially designated as a "Quiet Car". When we finally reached New Haven, there was no announcement of a Quiet Car opening up, although that first car up ahead of us was made available for new passengers boarding. By this point, the train was fully sold out for the rest of the journey into NYC.
On the return leg, we boarded at the Moynihan Trail Hall. Again, we walked toward the front of the train. And again, the car just behind the engine was empty and inaccessible. We quickly chose seats in that second car. This time, there was an overhead announcement about the quiet car. "There is no Quiet Car on this train. Sorry for the inconvenience. It might be added in New Haven, but for now - no Quiet Car. This train is fully sold out, so keep the seat next to you empty for onboarding passengers."
I was thankful for the communication about the Quiet Car, rather than being left wondering with no explanation. Once again, there was activity in New Haven - they switched the engine AND removed that first empty car. But no further announcements were made about the Quiet Car following that initial notification at NYP.
All in all, the train ride was a win. There can be no easier way to visit the heart of mid-town Manhattan at such a reasonable price. My take away from the experience is to NOT rely on the published amenities for my particular route. Just because it is in writing, doesn't make it so.