Ed Davis also rebounds and defends well, and while he's not a good scorer, he scores efficiently enough, and shoots a high enough percentage, that he's not a liability on the offensive end. The fact that he's also a good offensive rebounder and has a high enough IQ he can make the right path and knows where to be, helps.
Reggie Evans is a great rebounder, a passable defender, but is pretty much a liability on offense, despite the fact he's a great offensive rebounder, because he he can't hit a shot even when he's underneath the basket. At best, Evans is a 10-15 mpg player because of this. Of course, everyone pretty much agrees with this.