I look forward to giving it a listen... my own feeling before listening is that BB is far and away a better coach overall. The only edge Parcells might have is in motivating a particular type of player.
BB is the better X's & O's guy - we recognize him as a Defensive genius, but being a great Defensive mind means that you understand the offense just as well.
BB is also a better evaluator of talent - and knows what guys fit best into his system. He appreciates smart players and seems to have more than a few guys on his team who would one day make great coaches themselves.
BB motivates guys in his own way - mainly by being frank and honest in his expecations.
I'd say that Parcells is probably better taking a "problem child" player and turning them into productive players. Even some guys who aren't in the "problem" area yet can benefit from Parcell's approach to them.
Parcells does recognize that some players need to be treated kinder and carefully and some need to be kicked in the ***** - the Terry Glenn "she" comment is a good example... but he does recognize the different psyches at play with other players
I have a tough time imaginging BB using a "she" type comment in public... though I don't expect that type of player to be on BB's squad in the first place either.