Even if your advisor is not an eminent scholar, but widely known, you are fine. You may be better off with this well-known person than with another person with better research skills. But it is so much nicer when you have someone helping you establish yourself. If you are very competitive, you may not suit well with another competitive person unless there is a lot of goodwill from one party and respect from the other party. If you have strong beliefs, stay away from people who also have strong beliefs, especially if the other party does not have a lot of experience.
Ideology is extremely important when selecting advisors and committee members.
I experienced more ideological shocks that I thought possible. If your prospective advisor is a very busy person, you may look for someone else. It is good to be organized. When writing your dissertation, try to document all comments from committee members. If they have mainly been criticizing other folks without putting forward anything constructive or original, you may be better off with another person.