Fair enough, whether or not you're the same creature is a fairly minor point. I don't even know what that means rules wise. The rest I agree with.
It is different though, it can be dispelled, and if it is dispelled, you go back to your old INT. PAO is an active spell effect. As Darg pointed out, you can't pick and choose which parts of a spell effect to bring with you. If it were an instantaneous spell maybe, but it's permanent. So it's constantly acting on you to make you smarter, and to make you a snake person. You can't take the part you like with you and leave the rest behind.