I am also grateful to the Designers group on Ravelry, who pointed out where some matches didn't seem right. Most of those discrepancies have already been fixed, with one requiring a change in the software. Sock yarns weren't showing up with the substitutes that people expected, but we've been able to fix this now.
Others have used our new 'Report an issue' links to tell us where there's a problem with the data. Every problem reported gives us the chance to make the site better, so keep them coming.
It's also been fun to find out how you've used the site to find just the sub that you need, it's great to feel useful!