In the area I live, the "Mac reseller" is Best Buy.
If you want to have a technical discussion at an Apple Store and the employee you're talking with isn't cutting it, politely ask them if there's anyone more versed in what you want to talk about.
Most Apple Store employees have areas of expertise. You may be trying to have an in-depth OS X talk with an employee that only knows the basics of OS X, but could kick anyone's butt when it comes to photography on the Mac. That doesn't mean that there's not someone else available who could have a good technical conversation with you about OS X.
I'd recommend to anyone that goes into an Apple Store with a non-general question start with a Concierge (a person in an orange shirt). If you briefly explain your question to them, they should know the staff working that day well enough to find the best person for you to talk with.