Practically speaking, no knowledge is adequate.Learning is an ongoing process.So doing MBA or any other course definitely has a upper hand. But being a professional I can better understand whats the importance of experience once you enter into a corporate world.
Once you become a professional. you may come across a person who is just a graduate but is heading some department.Thats because he started his career immediately after his graduation. And this is a fact that every industry at some point of time do give weightage to the experience.
Now a days we have sach a facility that one can study and at the same time he can work also. Most of the well known management institutes have a program for working executives. Somewhere, company's also provide education leaves.
So education coming late in life has less impact compared to the lesser experience.But this also is to be noted that the success for the lesser qualified person is at a deminishing rate than compared to the better qualified person.