Thanks for your answers.
Maybe I wasn't clear enough regarding my question on whether using racetrack or reversal procedure, and using base turn or procedure turn with a reversal procedure:
I was looking at charts from a designer point of view and asking me: well, basically, racetrack and reversal, whether using base or procedure turn, have the same goal which is bringing the aircraft at the desired track and altitude.
So I was wondering why a procedure designer would rather choose a racetrack than a reversal, and if he/she chooses a reversal, what will make him/her decide to use a base or a procedure turn...
Difficult to explain... Hope someone followed me...