I made a similar decision to the GP -- it is not just that the octopus is intelligent (pigs are smart too, but I'm less perturbed by eating them). The octopus is such a vastly different creature to most/all other animals that we eat. To me, it feels more like eating a totally alien lifeform, which (subjectively, to me) is a greater pity than just eating something that is smart, but is pretty similar to all other animals (e.g. fish or mammals)