In my opinion the difference is that dealers/manufacturers like Duke, Verdant, and Atmasphere seem to be objective and don't always push their products on members. They offer genuine assistance, even if it means steering you down a different road.
What’s even more important is what those dealers/manufacturers mentioned above DON’T do. They NEVER put down another member’s recommendations or another competitive product. Dave and Troy have a long history of doing this (they’ve done it to me several times) to push their own products that to me completely crosses the line versus just mentioning their products or providing otherwise unbiased/useful info. IMHO if a dealer or manufacturer gets on here and starts bad-mouthing other products or member recommendations to push their own products they should be banned from this site. The whole idea of this site is to help each other by sharing valuable and often hard-won knowledge and personal experience, so when a dealer gets on here and undermines this in a biased effort to boost their own sales it damages not only the member experience but also the reputation of this site so I hope Audiogon gets more serious about stopping this egregious behavior.