A gun belt should be paired with the Mitt to distribute the G30's weight. I've been happy with the belts from Crossbreed and High Noon Holsters.
Updated Aug 23, 2013:
John's report was originally a PDF hosted by Adobe. They dropped the link. My apologies.
I've uploaded the file to Google Documents and updated the link above.
Thanks to those who have visited and left comments. I'm sorry to hear there are still some bad G36's floating around out there.
Remember, my advice is not to avoid the G36, but to put 100 rounds through one before buying. The seller who doesn't let you do that has a reason, and is saving you hundreds of dollars and a whole lot of grief.
To those compelled to leave anonymous criticisms, please review the site in full before typing.