To be fair, being 'HD' is such a huge range as to almost be meaningless. Just because another game did it in 'HD' doesn't mean that it was even close to the same level of detail. I'm not one who notices these things, so I'm not going to comment on the relative level of detail of FFXIII's graphics, but even if both games are HD it could be just as well comparing apples to oranges.

As far as I am concerned graphics looking good is of the utmost priority. Graphics being of high technical detail is not. Art style is way, way, way more important than the technical level of detail. Ten years from now FFXIII's graphics will look like an antiquated relic. What is important or not is if it still looks good.