a few weeks ago i bought a booq vyper XS2 and promptly returned it because it didn't fit the X300. the 4mm difference in length between the MB/MBA and X300 coupled with the stiffness of the vyper's design created a less-than-ideal fit. plus, they aren't built nearly as well as the photos lead one to believe, they're much thinner than shown, and the "non-scratch" interior only protects the top and bottom, leaving the nylon zipper perimeter able to wear away the edges of the X300's soft-touch coating. needless to say, i wouldn't recommend it.
all i want is a padded sleeve/case to give the X300 more protection inside my backpack. price isn't an issue as long as it fits, looks good enough to use on its own, and the build quality accurately matches the cost.
yeah, the coating can wear off. it should be more robust than previous thinkpad coatings but like anything you have to practice care in handling. it seems to be about the same coating as what's on my blackberry 8320 and it has survived quite a bit of abuse.