Larry Hurtado has a thoughtful, even-handed review of Ehrman’s book here. This subject area is one of Hurtado’s areas of expertise, his criticisms, though irenic in tone, are telling. My only addition would be toward the end. Ehrman seems completely unaware of OT antecedents to godhead thinking, something that’s my own specialty. But you only need to explore Hurtado’s exposure of points of weakness in Ehrman’s argumentation to see that Ehrman’s case comes nowhere close to being compelling.