Has anyone had any experience with their keychain tools?

http://www.trueutility.com/collections/all-products

I'm kind of skeptical -- it seems that if you're going to carry some sort of tool on your keychain, why not a small multitool?

I read Amazon reviews of a few products, and opinion seems kind of mixed.

Speaking of keychain tools, Chaosmagnet's recent post got me to put a Nitecore whistle on my keychain. It's so compact that there is no excuse for me not to have a signaling device. Thanks, man.