Those who are still thinking of 值得去读吗? will hardly get in top 3 business schools in the states, while those who have been admitted into a top 3 school would not ask such a question before the application.
I'll be going to a top 3 b-school for my field of study, and I just celebrated my 30th birthday less than one-month ago. (The acceptance was a nice birthday gift...) Someone who is 35+ got into Wharton this year.
So if you are a slightly older applicant, this is an encouragement for you.