I agree. Now what qualifies as relevant? Obviously "wow shiny" doesn't, how about "I've got this same model, runs great glws" does that count? Others here seem to think not, I think it does, it's an unsolicited confirmation of the reliability of the item in question right?
Which really brings us right back to where we started.
I would say no; how someone else's firearm performs isn't directly relevant. If a person wanted to talk about a firearm model in general then that should be done in relevant firearm sections.
As a general guide for what should be posted in a marketplace thread:
Statements such as "PM sent" are good. That can be useful for establishing a timeline for a seller, especially in instances where two or more users express interest in buying.
Questions that might be relevant to all potential buyers.
And that about it.