I have four G604 mouses. On three of them middle button broke about 6 - 9 months in use. I got two mouses "for free", as I was not required to send the old ones

I have four G604 mouses. On three of them middle button broke about 6 - 9 months in use. I got two mouses "for free", as I was not required to send the old ones back and they just sent me new ones from warranty. It's remarkable how many different kind of switches even within the same model they have. I think only two of the four have same feel to the switches. Some have stronger actuation force, and some are nearly noiseless. I have opened up few of the mouses and the switches are even different color, one had white and one had black switches. I will definitely look up these third party switches, if they are more consistent in quality than what ever the logitech puts in these.