Mr Buckfever: Here is my two cents worth. It's not to much different than deer hunting. I have had bear come off the side of a ridge and I would have sworn it was a herd of cows. I have also looked away from the bait for a second and when I looked up at it again the bear was all ready there (just like some deer). I would have to say that is more my norm that I look up and see them without hearing them.
The big thing you need to be concerned with is how much time you have to hunt and if you have the ability to pick and choose. I do and I let lots go. You may not want to do that being you are paying for a hunt/pressed for time and you have no idea how many bears are hitting the bait. You will have to chatt with the guide and see what he thinks about that.
The other thing I have found that may or may not be a factor with you is: Some new bear hunters get a little excited and take a less than great shot at a bear before it gets to the bait. They see it walking in or circling the area and they try to take a hard shot through trees. (read I am not saying you will but it does happen a lot).
My experience is that the bear will work his way to the bait or at least the shooting lane and you will get a clear shot if you wait. This is not always the case, as I have had a few wind me and run off. But if I waited they usually came back or came back a second night. If you keep seeing one hanging out in the brush and think you are being winded let your guide know and he may change the tree your in, to avoid your scent hitting the bear on his route in. Climbing tree stands are great for this (mobility). Again I would not worry about it or change a thing about the tree set up without talking to the guide first. Also on scent: I have found that practicing good scent control does increase the amount of bears that I see. Years ago I chewed tobacco and climbed a tree with work clothes on and shot a bear. But I see more bear ever since I started watching what I smelled like.
Thats about all I can think of that may help you,. Except that some bears are comfortable at the bait site and will stay there and eat. While others will grab something and run off with it and eat it in the brush. Then they return and grab something again. Just don't expect them all to just stick there head in the barrel and lay there eatting. Some wont stay around long.
Hope this helps! Good luck!
