Cons:if you buy the one with the 4 buttons, I find no flaw at all
I'm a long time computer user. As a web master the strain placed on your wrist can be overwelming and very dangerous. When I first got this mouse I inmediately found it confortable and very easy to use. Well, to better ilustrate how I feel about it, just think of this, I have 6 computers at home and 8 at work. They all have this mouse, and to avoid injury at the office I require all my workers to switch to this mouse. I hope this info is useful to you.