a model in which there is a middle ground. Is there really a difference in real-world evidence that says that one model conforms with reality more than does the other?
I would bet that that "middle ground" is not as stable as your argument and Cicero's is making it out to be. If you actually ask someone supposedly experiencing this "middle ground," I would meet they'd defer to adjectives like calm, bored, relaxed, with varying degrees of positive or negative feelings with varying degrees of intensity.
The fact - yes, fact - is that if you are alive, you're feeling something positive or negative. There is no "middle ground" and no "neutral" feeling. "Meh, I'm okay" is still positive, albeit at a low level of intensity.