I love the M650/L. I have some suggestions to help bring it to the next level and further evolve the mouse. First, please let the side buttons also be quiet like the mouse left and right buttons. Second, the mouse buttons are slowly starting to become unresponsive unless pressed firmly, please find a way to help the longevity of the mouse clicks. Third, the wheel would benefit from a more flat design, like your M330, as pushing the mouse wheel as a button with the round design is uncomfortable to perform. Finally, kindly adjust where the side buttons are located, they are awkward to press with the L model. I have to turn the mouse at an angle to be able to comfortably push the side buttons. The side button nearest the front is almost inaccessible with its positioning. Thanks!