In the beginning the mighty mouse is a bit strange, as there is only one physical button, but after a while you get used to it. Having 3 buttons AND expose all on your "mouse hand" really helps - it means that your left hand can be firmly glued to the lower-left of your keyboard - where it should be! (q,w,a,s,z,x,c,v all within reach). In fact, the norm is to use the middle button to show the dashboard - so in that configuration you would not need to go to the F9+ buttons unless you wanted brightess/volume/eject - in which case the Mouse hand is better. (Sorry all you lefties out there!)
I really did have problems with my (Apple no less) wireless mouse/KB when there was hefty traffic from my Airport card (running a card-card network). The response was jumpy and not nice - I suppose it could have been a bunch of other things though!
Quick Question - how often do you BTers need to pull out the old wired kb/m when there's an update/something goes wrong (batteries dying can do it!)
I know things are a lot better with Tiger (it tries to find BT peripherals during the startup right?).
I guess you are in a perfect position to try them both out though (if your dad is a kind fellow!). So let us know what you liked the best.