The main problem is that they immediately started to bend in the place where metal shaft connects with the plastic. And mind you, I'm not a death metal player, so when one of them broke in that exact connection I was quite dissapointed.
In addition to that, they are much lighter that the usual beaters, which obviously helps with the noise, but nevertheless could throw you off due to the changes in how you feel the kick.
In terms of silence they were ok, although they have a certain "smack" sound when they hit an electronic kick drum pad, which others beaters (silent or not) I have used. This a not that big of a deal, since that smack is more high pitched, therefore easier to muffle, but it's a strange thing for a silent beater to have nonetheless.
With all that and a quite high price I would not recommend this
