Earlier quoted context omitted.
Maybe for now, you could more manually garden the landing page, using feed of recent comments, so even if they're infrequent, they can be emphasized.
I'm trying to keep the homepage as free of clutter as possible but I do think this would add a bit of personality to the site (as opposed to the sterile, crowdsourced feel that you mentioned before). I'll have a think about a creative way to put this in.
Gotcha. How about this then: The users are putting in some nice personal words about each of their submissions. However, these extremely valuable words kind of appear as if they're coming from the vendor's site (watering them down, making them seem like catalog copy).
Suggestion: Put the words and user's avatar closer together. Move the vendor-link farther way.
This will emphasize the conversation. Perhaps even go crazy with a word bubble shape a la Twitter?