Leaving the Thunder could be a tough decision for Durant. Westbrook is super talented but it's hard to tell if it translates to winning. The way Durant talks about Westbrook, it sounds link he really likes him. I'm not so sure he would leave the Thunder unless there is another top star he has an opportunity to pair with. Both of them might be reluctant to chase greener pastures.
KD should have a lot more left, but he could become injury riddled.