He is as bad on defense as he is good on offense. His defense has been bolstered by the fact Stew has played quite a few minutes next to him.
The Piston's weak schedule also means Duren has been going up against weak big men rotations. The only good bigs he has faced were Houston and Cleveland. I think he had something like 14 points combined against those teams. Although, he only played 12 mins in the Houston game because he got ejected.
I do see quite a few Pistons fans saying he will get a max contract this summer. That would be a disaster.