As previous posts have described Eskalon is great... apart from the simple business of keeping the trains connected to each other! Using the semi-permanent bar works for push-pull operations but it does mean that one loco is tied up with 1 duty as uncoupling the loco from the train means lifting from the track.
The design flaw in the D13/D16 model means the hook coupler keeps catching on the end of the loco which makes operations difficult and to honest i have become so frustrated i've begun thinking of ditching the layout and starting again in a different scale...
But lets try one final gambit. If the hook couplers keep catching on the loco why not make them a bit longer... So i have thanks to a couple of butchered coupling bars and a bit of superglue! The modified couplers seem to work great both in pushing and pulling passenger trains. They stick out a bit far but as long as i can enjoy some train operation without trains becoming detached or derailed i'm cool with that.