I have had an original run of the Xlight that I got at the 2006 SHOT show. It was given to me by the folks at LRI. This was before they were on the market. It has been on my keys since with no issues.
Just remember it is a keychain light and is not meant to be bombproof.

As far as water-proofing don't bother; lights that run on low power don't need to be waterproof. Just turn on a photon and toss it in a glass of water it will keep working.