Man... I just recently bought a Filco, and I have the Topre sitting in the storage, and seeing all these videos made me miss my Topre.
I know, I know. I should bust it out again, and I will eventually. I'm just spending time getting acclimated to this Filco.
That said, since I've had the Topre in storage for a couple of weeks, I don't remember the exact details... BUT, as all those videos show, it's a quiet keyboard. It's definitely quieter than my Filco, and I definitely remember it NOT pinging, IIRC. When I first got the Filco I immediately noticed heavy pinging, so that probably means there wasn't that much ping, or any at all, with the Topre to begin with.