Yep, I've also spent many hours watcging animals that were out of range and napping. But those are apples and oranges with respect to setting up in a spot where animals can pass through at any time.
I'd say that depends on the situation - including size of the area, type of vegetation, etc. We've sat where you could see elk coming from over a mile away and didnt chamber untill they were under the horizon of the knoll we were sitting on. Ended up passing on a 25 foot shot and taking one at at around 35 yards.
