Funny, I'm pretty sure I got a sale today for exactly this reason - I directed her to positive feedback and a link to a blog feature that I'd included in my listings!
For me, as a new shop with products that look better in real life (that's a photo issue I'm still trying to resolve!!), having feedback gives that extra boost of confidence, especially when buying online. We are in a very competitive market place and we're here to make sales, so every little bit helps!!!
And I totally agree that we work hard, we've earned that positive feedback!!
Oh - and I did ask permission before using, even though it's public I think it's just the right thing to do to ask someone when you're about to cut and paste and display their words!!
I say, go for it! :)