From what the locals have told us, the cougars are not a problem so long as they have plenty to eat. They are nocturnal, so you seldom see them during the day.
The only problems we've heard about with bears are the stupids and the sow that inadvertently gets bothered by your presence near the cub(s). They do not want to be near you any more than you should want to be near them. The stupids I mentioned, are just plain dumb, and shouldn't be there to start with.
We've encountered a lot of bear over the last 15 years that we've made our trips to the rockies. Some have raised the hair on the back of my neck, just because they were so close and soooo big. But, none of them were aggressive towards us. I really haven't noticed much difference in the behavior of the black and the grizzly.
Last year was a bit concerned with presence of so many wolf. They did not seem be the least bit afraid of us.