The game has a lot of bugs, but it's fun regardless.
I've experianced the following so far:
Coyotes that run faster then horses at full speed. They were chasing someone and kept running past them. It was a bit scary, and no I did not bother to help the poor stranger.
A stationary stagecoach that was bouncing as if it was going over heavy terrain, or being used for something dirty yet fun.
My character occasionaly gets stuck when mounting or dismounting from any stead or coach. It's caused me to turn off the game at least once to fix it.
A nice big red and black screen that says nothing other then "Error!"
Hanging and crashes during loading screens when in multiplayer modes. Randomly kicked from group and into different sessions. It's so common that I do not bother with mp unless there are people in my friends list for easy re-invites. Oddly enough, you do not lose voice communication when this happens.
I'm amazed at how many bugs are present in this game, but even more impressed that I enjoy playing it.