I've got three ladders, and they are all around 15 feet. Last year, had one set up with only 2 ladder sections, so it was about 12 feet, because it was in a swampy area with few decent trees, and that was the highest option. Saw some deer, and didn't get busted. It was in a fairly thick, bushy tree.
In my experience, I have a hard time finding a tree I can get up more than 15 or so in my climber.