I find it profoundly annoying that most shows that deal with supernatural beings go out of their way to highlight that the human way is the best way. Are we really that insecure that we need constant validation? God forbid someone else is happy being what they are; only humans are the "proper" species, so everyone should aspire to be that. As much as it pains me to see that Cas is suffering, I'd rather have that than see his accept that humanity is the only good thing in the world. Everyone keeps saying in-verse how angels are all emotionally challenged and how that makes them inferior to humans, but the way they're written completely debunks that! They clearly know love, they know wrath, they know sorrow - basically the full spectre of emotions, they just feel it differently. So the whole "humans are better" thing is even more annoying in light of that. :(
Speaking of Ephraim, I liked him (esp. the way he tossed Dean aside XDDD). He was tragically wrong in his perception of human pain, so of course he had to go, but he was a great character (but we all know what happens to great characters on SPN).