If you ask me if my guitar is heavy, I'll weigh it on my bathroom scale, tell you how much it weighs and let you decide for yourself
I like to stay away from subjective information when selling items. It helps avoid buyer disatisfaction. Let's put it another way, if you play the same guitar with gunky frets, old strings and rattle-y action and then clean it up so it has polished frets, new strings, and give it a nice setup, which one will you think is more resonant? Probably the latter. But has anything about the guitar actually changed? I'd say no. Of course I can tell if a guitar is resonant, but IMO, that's something for the player to decide for themselves, not for me to tell them. Hey no one's making anyone buy a guitar over the internet without playing it first. If you decide to then IMO you need to trust that the brand you're after has more winners than clunkers and be alert for signs that the guitar might have been abused in such a way that the intitial "goodness" of it might have been compromised. Disagree if you wish, but I've sold plenty of guitars and AFAIK, no one feels like I've burned them. So I must be doing something right.
Even if I don't know anything about guitars.
-Austin