For me it's probably when a combat goes on for more than 45 minutes, unless it's a titanic battle with lots of cannon fodder to toss around. This doesn't occur to me if it's a long fight and I feel I'm winning by a margin, or just about to lose. It's more when I KNOW we're going to win, but the creature in question has heaps o' hitpoints. The GM is usually wise to cut the creature's stats down to fit the situation, especially if it's apparent it's getting the tar beat out of it and will lose anyway.
I wonder if there is a "sweet spot" for the average length of a combat before things start to feel like "hit/miss, ho/hum". Or does it depend 100% on the group, the context, and all else?
The reason I'm asking is because I'm toying with the idea of a special type of creature that "drops dead" in a certain average number of rounds, and basing their hitpoints on that guesstimate, rather than basing hitpoints on their threat ranks. Just playing with the idea, mind you...
