The last time I rode coach overnight, I was seated in a row with a mom and her 2 young boys. I had the window seat, the mom sat next to me on the aisle, and the boys were in the 2 seats across the aisle. Actually, it wasn't that bad. They boys were very well behaved. The car was pretty quiet through the night. The only reason I didn't get as much sleep as I wanted was because the seat of the Amfleet 2 coach seemed like it was made of concrete. Perhaps the interior refresh has taken care of that.
Another advantage over the sleeper is the low expectations regarding on-board service. When I went, there was traditional dining for coach passengers -- except that the sleepers were filled that night, so no dinner reservations available. But with the low fare I paid, I wasn't bothered too much about having a pizza in the cafe car. People paying $500 for a sleeper tend to get all bent out of shape about flex dining, being forced to eat flex dining in their rooms, or even on the trains with restored traditional dining, having the diner be out of what they want to eat. Obviously, Amtrak needs to fix that stuff, but at the current time, it might well be that traveling the long-distance trains in coach might be the preferred way to go. You just have to be prepared, and also try your best to travel when it's not too busy.