The MX4 was an instant buy for me and should be delivered tomorrow. It’s been about six years since they released a proper replacement, as I don’t count the 3S as one. I’ve been using my MX3 for five years and, apart from the soft-touch rubber wearing out (though it doesn’t look too bad considering five years of heavy use), the buttons are still as good as day one.
I’ve bought every generation since the Revolution, and with each one the left/right buttons usually failed after a year or so, resulting in a double-click instead of a single click—which is really annoying. But every time that happened, Logitech support, once they verified my purchase, always asked me to physically destroy the mouse and send them photo evidence, then they always sent me a new retail replacement at no cost to me, not even a temporary hold on my card which is annoying with Apple. Their service was insanely good—though I’m not sure how it is these days.
I’m honestly surprised the MX3 has lasted as long as it has without any issues. Hopefully the MX4 will hold up just as well, especially considering how expensive it is for a mouse