Asking most home theater/audio sales guys for technical details on a product they sell is like asking a blind man how many fingers you are holding up.

Most of the people (like Gonk and others) here know way more than pretty much any salesperson you will meet.

In my experience, for most sales people, it's their job and not their passion, so other than learning the surface details about the products, they don't really go deeper than that.

Exceptions exist, but are not the norm.