I think you could make a decent argument that David Price is done as an "Ace". That FB is down by a considerable margin, and I'm not sure if the new rock bottom BB rate is true talent / sustainable.
I think you could also make a weak argument that David Price never really was a legitimate Ace! His fWAR pitcher ranks by year since 2010 are: 28th, 20th, 8th, 15th.
His yearly peers are often guys like Kuroda, Shields, and Lester, all of which I would consider strong #2s and not Aces.
I generally consider the "Aces" to be top 10 pitchers, and Price hasn't been that in 3 of his 4 full years.
But then you look at 2010-2013 in totality and there he is, 8th in total pitching fWAR.
If he's been a true Ace, then he's done it with consistency and not big upside. I guess you could say that he's a second tier #1. I mean, he's clearly been a rung below Felix-Kershaw-Lee-Verlander. And on top of that, there are several guys who might have leaped him this year in the arbitrary pitcher rank ladder, such as Fernandez, Scherzer, Sale, Darvish, Harvey , and Anibal.