Very cool. I can live with a noisier scrollwheel, but the buttons get more use and can be more disturbing to the user and neighbors.
Do the buttons produce any clicking sound? I have the Logitech Cordless Desktop MX 5500 Revolution which includes the MX Revolution mouse and it's definitely not silent. Have another Logitech mouse which has the shape of the M500, and it's relatively quiet though the battery life is poor.
Haven't had much luck with Logitech as their buttons are really levers and they produce a high pitch clicky sound. Design-wise and ergonomics are great, but haven't found a model with quiet buttons. As for their keyboards, I went through four Logitechs before I found the K800 to be the quietest. Not that the preceding keyboards were not quiet, but they have a short shelf life before they become increasingly louder, especially the spacebars.
I find Logitech to be unreliable in terms of their buttons, had to operate on two of my Logitech mice to fix their left buttons.
I also had some Logitech keyboards and they were also lousy.
I have learned my lesson now and stay away from Logitech.
but for silent buttons, I too have never found a silent mouse. As long as it has buttons, it has some kind of clicking noise. Some are noisier than others.