It is really close to the original, except the effect of the skeg. Speed is correct: backwards a little bit faster than ahead; steering is realistic: you need both thrusters for a significant course change, not just one; the heeling is correct: it's really amazing, how much the original ship heels over when turning around with full thrust! There are two ways to step sideways, one with more thrust than the other. Both is working in game too.
I just miss the tremendous effect of the skeg. If the tug is working backwards at the stern of the towed ship, the risk of getting the slipped towing rope under the keel and into the props is high. Therefor the tugs master turns fast to one side and the skeg helps turning and stopping the ship almost at once.
Cheers