I retired my Apple USB Mouse M4848 in favor of an aftermarket two button non-scrolling mouse also. My Apple USB Keyboard M2452 drives me nuts partly because the home position tactile nubs were moved from (d,k) to (f,j) positions. Also on my 10.3.9 system there are some long irregular delays during the composing a reply during which I can out type the display. I haven't tracked this down yet, but it is slightly easier composing offline. Never had this problem on 9.2 or earlier on any system.