Their RS success, yes. However, once the postseason comes around the Spurs may be the most susceptible to dropping in status due to injury. What makes the Spurs so tough to beat is their adaptability and versatility; they can play any style of basketball and do it better than just about any other team out there. That is able to be done because of the diversity of the roster. Lets say Diaw gets hurt and misses the playoffs. In that scenario the Spurs would be ed just as well if it were Duncan, Leonard, Parker, or Manu. The Spurs as I see it have 7-8 unreplaceable pieces in Tim, Kawhi, Manu, Tony, Boris, Splitter, Green, and Mills (though CoJo looks like he might be able to cover should Mills go down). Without one of those players the Spurs lose a facet of their game and become very vulnerable. While its true they can beat most teams on chemistry and system-play alone, to beat the teams with more talent like OKC/Dallas/Chicago/Golden State/Portland they'll need to be at full strength to overcome that disadvantage.