Most people that say they are 30-35 feet up a tree do not realize how high they actually are. I've seen people say wow we must be up 60 feet when we were only on top of an oil tank that was 25 feet high.. When youre up, looking down, things look alot higher, so people tend to think they are higher than they really are..
Theres no need to go anything more than 25 feet high.. use a 30 foot hoist and you'll know when youre at 25 when you start lifting your bow.. otherwise just go as high as you feel comfortable.. honestly I go 20 and thats enough for me..