Personally, I think Robin has gotten it right given all the pitfalls and administrative headaches of a negative feedback tool - and don’t want Pinside to turn primarily into a market site that tries to referee wide ranging expectations between members. The buying/selling aspect of the hobby while an important, fun part is already too dominant on the site IMO. The lack of positive feedback from respected, experienced Pinsiders should prompt further investigation (forum search, etc.) and “proceed with caution.” Having the ability to start a thread for truly bad, or good, experiences seems like the best option to me.

It's the same as the rating system, the raw number is worthless but reading the comments with an eye to who left them can be helpful.