While I enjoy the free roam, it is already becoming a little tiresome, I'm sorry to say. Apart from the assaulting gang hideouts, there's little in the way of orchestrated activities. Sure fighting bears and crashing wagons off bridges and cliffs is always a laugh (highlights of the evening for me was seeing Fab getting pounced upon by three bears at once and me crashing my wagon off the railway bridge, also taking Phat and his horse to their deaths), but there's only so much you do in this mode. There's not many people about, no trains, etc. Hunting for the rare animals will probably require a lot patience and bore people fairly quickly. I think it's wise of Rockstar to release this co-op pack at the end of the month. They would be wise also to add trains, lassos, and the same kind of random attacks and events you get in SP. Just make it more interesting.
I don't want to sound like I'm complaining about the game already - it's brilliant - but I think you're probably all feeling like this after a few sessions online. I know Jonno does, he grew tired last night. The free roam is a great concept but needs work I feel.