For some reason both Windows and Mac users give me funny looks when the question of one button mice on Macs comes up in conversation. Perhaps it is because I use a mouse on my Mac with two functioning buttons. Cut, copy & paste etc and other context sensitive choices are available on the right button.
I changed from the Apple Pro Mouse as I didn't enjoy using it for extended sessions. For some reason I haven't found an official Apple mouse that I can live with since the Apple Desktop Bus Mouse II on the 9600 Macs. I reckon that it is only me as I never hear of anyone else wanting to change their official Apple mice. I do like the Apple Pro Keyboard though.