I hardly ever have time to help the random strangers out in the wilderness. The victim always ends up getting killed before I've ever figured out where they are
On the other hand, the ones who approach you in town saying the store has been robbed or their horse has been stolen (or whatever) are usually pretty good. I spent 20 minutes chasing down a horse rustler yesterday, because I was on a slow-ass mule. But I caught the varmint in the end, sure dang.
I like that there's so many random events like that though. It makes the environment feel like it's alive and that the people matter. I accidentally killed some random guy in a town and for ages after that horse breaking missions weren't available round there. It took a few game days before somebody replaced him.
It's not as immediately grabbing as GTA4 was, but the world just works. I can't wait to get online and start posse-ing it up.