This my second m705 logitech marathon. My first mouse was a gift from someone who had been using their own marathon for a while. My own lasted a long time before the receiving usb stopped working (in hindsight you might be able to purchase a spare from logitech nz). The good (why I bought a second): the batteries last a really long time (even when I forgot to turn the mouse off), the mouse often (very often) became a flying mouse when I moved my laptop (yet this never reflected in its performance), the two buttons on the left side are well placed, programmable, easy to use, and really, really easy to get used to, the fast and slow scroll speeds on the wheel are very useful, the mouse feels good and is easy to use with my extra large women's/ large men's hand, the response from the clicking and moving of the mouse is very accurate, the mouse works on most surfaces, it's possible to store the usb inside the bottom of the mouse with the batteries), and finally the materials make it feel nice in the hand. The not so good (what I wish logitech would improve): the ability to give the mouse a proper clean (it's impossible to unscrew the mouse to clean the internals without damaging the mouse, the closest you can get to the laser is wiping it from the outside, and there is a little gap between the laser and the edge of the mouse (obviously), that can allow the build up of gunk, which is difficult to remove/ clean), the rubber type stuff on the sides of the mouse wear away first (my advice regarding cleaning would be to use a cloth with a gentle, gentle soap), the ‘click’ from the left and right pointer buttons (on top of the mouse) might be loud for some (it doesn't bother me, to me it sounds only slightly louder than the typing on a keyboard). These suggested improvements only occurred a while after using my previous marathon. Overall I'm happy with the logitech marathon, and it is the mouse I would advise and buy for others.
