It depends on bioload, how many plants you have, filtration, etc.
I do about 60-70% a week. I have a ton of plants and filtration, but also a significant bioload (6 discus and a lot of little fish in a 65 gallon).
I don't understand people only doing 10% or 33% or whatever. As long as you are using some kind of pump/Python, etc., once you're doing the actual water change, 60-70% is no more work than 10%.