You make a good point...one is a full OS on a tablet and the other has an os made for a tablet. I would offer the point that perhaps the iPad would be a better fit because it's designed to be a tablet, rather than trying to be a computer squeezed into a tablet. It does what it's made to do, not what it wishes it could do. It could boil down to the concept of do you want to do a fair job at a lot of things, or would you rather do a superior job at a few things?
Please, just try a Surface 2 and talk based at least on your experience, not rumors.
And remember iOS is based on OSX. Does it make it a bad mobile OS? Would it be much better if it had been done "from the ground up" for mobile?.... I don't think so.