I finally had the chance to ride the Next Gen Acela (I was out of the country for two months). I rode 2169 from NYP to PHL on 12/5. I received a text notification a good five hours ahead of time that the train was running an hour late. I considered switching to 2167, but in the end decided to just wait it out. The delay gradually increased from 60 to 90+ minutes and then we were further delayed by super slow speeds from the tunnel exit to Secaucus. Therefore we ended up getting to PHL almost two hours late, but based on my conversations with the NYP Red Cap, the issue wasn't with the train itself but with infrastructure issues in Connecticut and near Secaucus.

The new trains are definitely a smoother ride; still some bumps but none of the violent jerks that would send objects flying. The seats are hard and the head supports don't allow you to sit at an angle as I prefer to do. Also, at least in first class, the train was quite noisy, although I imagine that's because we are right behind the engine, so I assume it's quieter further back.

The tray tables are a huge improvement mainly because they are much more stable.

I thought the service in first class was slower than in the older trains mainly because the galley is further away. I also miss seat 16A where you can turn around, hold out your glass and get a refill! However there were three first class attendants rather than the usual two, so not sure if that was just on this particular train or an upgrade system wide.

Also, it was the correct decision to wait for this train because Amtrak sent me a $150 coupon as an apology for the delay; last time I experienced a delay I only received $25!