Big enough for my (relatively large) hands lies comfortably in the hand, slides well across the table, high sampling rate, sufficient programmable (the Logitech software, it always manages to disappoint you. I'm glad if I since once everything set up hab how I want it, then the stored in the mouse itself and finished).
I use the mouse even when working and the charge lasts maybe so for 3 days. 'm Not even sure ... but if you have the USB cable is always at hand (which well adapts to the form) then you have just a while a corded mouse when the battery is empty again - and on we go. Storing the transmitter in the mouse is also very practical.