Honestly very quiet, quieter than most of my Cherry boards. Maybe my RACE (no plate) with reds switches and o-rings may be quieter?
I just replaced the E switch on my poker and went ahead and put o-rings on it. (Need PBT switches - as I've grown used to the feel of PBT and POM keys for the last 3 months).
And I was thoroughly surprised with how quiet black switches + o-rings really are. And the fact that the o-rings don't hinder me like they did on a cherry mx blue.
Lol, I preferred lighter boards until I got the 55g. Liked that thing so much I was tempted to get another 55g, but the curiosity of trying the lighter Topres was just digging at my skull. Pulled the trigger on a Type-S just now
) 
I kinda want to get a 45g uniform, simply because I like the lightness of my cherry mx reds -> and if I really do learn to love torpe, then it will be my main keyboard for my desk.... so I'd like to get it right on the first try.

But thanks for the info, I was aware the silencing was for the upstroke -> I'll keep that in mind. I'm still contemplating getting full sized, which would be variable weight.
Additionally, how are they silenced? Is it similar to the o-ring modification underneath the topre switch itself?