Man, I wish I had been visiting this forum more frequently when this was originally posted. I'm the supervisor of our Geek Squad and I could've helped you. I can't speak for all stores so I won't even try to defend the Knoxville store (though I'm pretty sure I'm in the same district as them)
Oh, and I've owned a Mac for almost 2 years now and I love it. Also 90% of the computers we fix have Vista on them so I'm pretty comfortable there as well.