mettelus
I just replaced a Logitech MK710 keyboard/MK705 mouse with the same thing. I had literally worn several letters off the original keyboard and polished most of the rest. The thing about the marathon mouse I cannot live without is the brass mouse wheel. Six years later it is the same thing (just cheaper to buy now). I work with large documents (100+ pages) a lot and cannot take "slow scrolling." When that wheel ratchet is disengaged, documents will scroll as fast as the graphics will tolerate (20+ pages per second). That particular mouse has 5 buttons as it is (three on the thumb), so I have never had "need" for a middle button (Win7 supports 5 buttons without installing mouse-specific drivers as well, not sure about Win10). That particular point is of interest to some, as I have seen issues reported from the Logitech (SetPoint) drivers in the past.
I am running Windows 10 with the M705 Marathon as a default HID-compliant mouse. In the Microsoft control panel I only see 2 buttons available.
So far I have avoided the Logitech SetPoint software, as the MS mouse drivers are working trouble free, but I am curious about the third thumb button thingy...