I have to say that I have a weird exception in my collection for Thurn and Taxis. There was an era where I played it to be social on BSW, and it was suitable for that. I also recall liking the board. Haven't played in years though.
I haven't played this game in years and years, but my lingering memory of the game is that ... it's brown. The map was brown, the cards were brown, the box was brown. I think even the player pieces were differing shades of brown??? That part might not be true.
In the annals of boring Eurogame themes, "setting up postal routes in medieval Germany" has to take some sort of prize.