I would have to agree that an athlete should do both. However I would concentrate more on the wide stance to parallel, and use the deep oly squats as a supplemental.
The reason for this is that if you can squat 500lbs to parallel in a wide stance...then you will easily squat 250 in the oly version. The converse is not true. A 250 lb oly style squatter would probably get crushed under 500lb...even though he is using the wide stance shorter range of motion. The reason...he doesnt have the UPPER BODY to support it. People seem to forget the importance of the upper body in squatting...and in running and jumping for that matter. Wanna run faster....bring up your rear delts so your arms can move faster.