I'm still of the opinion that 95% of people, including shop owners and people on here (including myself!) couldn't differentiate between 'ping' and 'ripeness' (i.e. whether it's knocked/played in or not) of a bat.
And I don't think the in shop tap up does little more than reassure the ego
And that's not before you consider sheer wood weight - how many would say a M&H Distinction 'pings' more than an M&H Original mid or Harlequin

Certainly (genuinely) the 2 best rebounders I've owned were a Distinction and an ex pro Mongoose...Obscene power (standing and reflective) from the pair of them but never could tell if it was ping of the silly amounts of wood behind it!
Doesn't change a thing of course. And sometimes it's almost a nice surprise to find a plank amongst the forest, just to remind you that sometimes the mallets doesn't always fly back through your wrist