I admire anyone with hutzpah and those with vision, it's how small goes big. I also understand making outlandish statements can be viewed as "link bait" and hopefully draw attention or at least a look to a website.
But - sometimes saying crazy stuff brands you as just that especially if you don't have the goods to back it up.
Bringing this back to what we were talking about - the effectiveness of signature links, if I had a signature saying
A more effective link builder than Google"
I had better have something to back that up. Never mind the SEO benefits of the signature, if I can't prove that out of the box, I'm sunk.
Look at your signature as a way to attract positive credible attention to your website and don't focus so much on the link pop it may or may not give you.