CAP or no CAP, chaos will reign.
I think FLP (https://groups.csail.mit.edu/tds/papers/Lynch/jacm85.pdf) is better way to think about systems.
I think CAP is not as relevant in the cloud because the complexity is so high that nobody even knows what is going on, so the just C part, regardless of the other letters, is ridiculously difficult even on a single computer. A book can be written just to explain write(2)'s surprise attacks.
So you think you have guarantees whatever the designers said they have AP or CP, and yet.. the impossible will happen twice a day (and 3 times at night when its your on-call).