>>106192801
Once you have pause, stop, next, previous, mute, volume buttons for the right hand on your keyboard, you can never go back.

Besides, those extra programmable macros on the left side are going to be useful if you're doing 3d applications a lot, or if you have games that can take advantage of them. Then there are things more tailored to office users, which is a staple of Logitech's membrane offerings.