Personally, I don't think it matter as much as some people may think. The big question, the most important of all questions, is do the players buy in? Do they embrace the scheme and believe in it? But, of course, these are not the only factors on rather or not a team will be successful. Clearly, you have to have talent, as well. Furthermore, has the Head Coach surrounded himself with people who understand what the Head Coach wants and know how to implement it (e.g. coordinators)? If I'm not mistaken, both kinds of coaches have had success in the NFL...but a number of other things have to come to fruition in order for them to be successful.