I bought one of the keychain cams but made the mistake of not properly reading the link you gave us and ended up with a version 1. I sold it to a workmate and ordered a version 3.
Anyhow since the keychain was no good I made another clip with my act5k. It's a little dissapointing for picture quality, it's big, it's heavy and it was kind of expensive for what it is. On the up side it is meant to be shock resistant ( offset by being big and heavy ) and waterproof to 3m ( or something ). I know youtube is not good for camparisons but anyway.....