I got a loan of someone's old Mighty Mouse today. The thing is a classic case of something that was well designed but not well engineered, so that the things that sound good on paper are the things that cause the mouse to fail in practise. Let's consider them -
1. The design is like an extension of the single button Pro Mouse with touch-sensitive technology to detect which button you want to press. So you can click with your whole hand, but by pressing down on the right you right click, or by pressing down on the scroll ball you can middle click. It also has touch sensitive side buttons, and supposedly OS X has the ability to define points around the side of the mouse as additional buttons.
2. It has a nice little miniature trackball that allows you to scroll in all directions. If it worked, it would probably be a rather pleasant way of scrolling through web pages or documents.
Now, how the implementation fails -
1. Because they want to preserve the ability to click with your hand, you now have a problem - if you are pressing down on the surface with your fingers, how does the mouse know whether you're left clicking, or pressing all the buttons at once? This is where the touch sensitive controls come into play... if more than one finger is rested on the mouse, any press will be counted as a left click. So if you want to right click you have to lift all your fingers off and press down on the right hand side with a single finger only. Same story for middle click. This is rather inconvenient if you use the right and middle buttons frequently. I guess in OS X where they don't use the other buttons as much, this is an acceptable trade off, but in Windows or Linux, not as much so.
The force-sensitive buttons on the side are a bit weird. If you look inside the mouse (I'd make my own, but there's billions of them up if you google 'Mighty Mouse disassembly') you'd see that unlike the weird contacts for the top mouse buttons, they push against contacts on the PCB... I'm not entirely sure why they didn't just use run of the mill tactile switches for them. Since I don't think cost is an issue here, I think Apple was trying to keep to it's whole 'touch sensitive' theme in places where it maybe wasn't best suited.
Some reviews complained that the side buttons are put in a bad place, but I didnt use the mouse enough to have an opinion either way.
2. As I kinda hinted above, the trackball is rather unreliable. In fact, if you google Mighty Mouse, you'll see loads of links for people complaining about dead scroll wheels, and offering various cleaning tips. I have seen some people say that these cleaning tips do not work, and indeed, despite disassebling the one I had completely, I could not get the thing to work. I was told that the previous owner attempted to disassemble and repair it, so it might have been damaged there.
The problem is that balls pick up dirt, but in a ball this small, the tiny mechanism gets clogged up with unacceptable amounts of dirt too easily. Furthermore, it's not easy to remove the ball (to open the mouse you have to break open a seal on it's underside which is sealed on by glue, fortunately this had already been done when I got it) so it's hard for the average user to clean it (the usual advice given is to damp a cloth with Isopropanol, turn the mouse upside down and roll the ball around in it, or blow into the ball with an airduster) A design like the IBM Scrollpoint which includes a trackpoint as a scroller would be a much more effective solution, as it requires no cleaning, and involves less effort as you are just applying force to stick as opposed to constantly rotating a ball in a manner which will probably tire your fingers out.
Hell, even if it was implemented perfectly, it's still miles inferior to either my CST or KEM. It's going back to the person I loaned it from tomorrow.
