Reibe is still pretty solid. His defense still needs some work and he's not a bucket like Reed, but he is good for 6-10 pts depending on how much time he plays and rebounds pretty well. He does his job well of spelling Reed and giving extended minutes if he has foul trouble, and the more minutes he plays in a game the more impact he seems to have.
That said, Reed is better right now and should get most of the minutes, this isn't a center by committee year. However, I do think Hurley should have a little quicker hook on Reed when he's playing one of his lackidasical games and put Reibe for some extended time.
I'm not sure what Reibe's camp could really be that unhappy about, he's playing about 15 mpg (to Reed's 25 mpg). I can't imagine Hurley would have suggested he would get more than that this year with senior Reed on the team. Granted its been more like 10 mpg recently since Tarris has been playing well, but he still gets 15-20 mpg occasionally.