The superliners were supposed to have EP brake, not ECP brake. ECP brake is microprocessor controlled and does not actually change the brake pipe drop. Its as close to a train being a train simulator as you can get. It just works. The air brake rack on each car has this strange electronic device that replaces the control valve thats normally all pnumatic. ECP is not an entirely new new thing, the freight railroads have been messing with it on long coal drags for well over 10 years now. The EP brake is what NJ Transit uses, i think some metra equipment, Acela express, and septa MUs.
Operation of the ECP set to passengers wont feel any different. The cab car still slams around the train as the engine bumps in and out of the consist as the blended brake apples and releases on the engine. Operating from the engine can feel a little different depending who is running because there is a secret about this system i cannot reveal here but it basically can allow you to run a lot smoother if you know what you are doing with it. Supposedly MARC is going to get the same system but idk. I dont see it being good for push pull service. The Amtrak set has a Knorr system in the engine and a Wabtec system in the cab car. The Knorr system sets up and tests pretty quick, but a lot more to deal with than your standard air brake set up. The Wabtec system takes FOREVER to set up. Its a mess. Every time you have to cut in and out of the system or shut it down for any reason you have to go thru the whole process of it discovering all the cars, the EOT, etc. Just a lot of work for a commuter rail ops. For the auto train however, its golden. I could see this making the auto train work much better for them.
No good deed goes unpunished.