Just played a HITS & Couriers game, 4 players vs the AI. Everything went super smoothly. The couriers are much faster moving it seems and the whole game felt more stable and less laggy.
The replay feature works on MP games too and I can see this being of much interest to MP groups who can discuss how a battle went, particularly if all players load the replay and start it running aat the same time.
I did detect what could be a bug in the replay in that when a unit failed morale and withdrew, its combat block remained in position where it was fighting for some time. I saw this happen twice with cavalry units.
Apart from that everything feels much improved, even the graophics seemed crisper.