The CZ #5 of the 19th of this month was a pretty full train - believe I heard some of the Amtrak crew talk about it being sold out btwn DEN and SLC... and it felt full, ie, there wasn't a lot of free space for anything - best to hunker down in one's seat and stay there [sSL was always full, still full at 2am with talkers (no lounge lizards); dinner seatings run until 930 (ours was 9pm), etc]. My question has to do with the cost of adding another coach car to a consist. I understand when a consist get's too long the train has to be double spotted at some stations. ... but given the "hot-rod" nature of a 9 or 10 car CZ, I'm assuming adding another coach car or two doesn't affect performance, ie, no need to add another loco and associated costs. Where does the added cost come in? Added staff? If so, is that a significant number/cost? Yes we were able to travel pretty much armpit to armpit with the cars we had... but wondering about the experience, and if adding one or maybe even two extra cars wouldn't have added to the experience for all concerned, and resulted in more believers for future trips (ie, return passengers). Or, is this a question of simply not being enough extra cars in the system to routinely add cars to fullish trains?