Since getting my iMac a couple years ago I've pretty much used Apple products for all of my computing needs. The iMac came with a USB Apple Mighty Mouse. I quickly upgraded to the Bluetooth version but both were limited by the same problem, the scroll ball. In theory the scroll ball was a great idea. I could scroll and pan in any direction (even diagonally) and I could use it as a third button. The problem (with both) was that after a month or two of heavy use the ball would become gunked up and stop working. I found several ways to clean it but it would always get gunked up quickly and stop working.
Then I received the Apple Magic Mouse for my birthday. This is, in my opinion, is 90% of the way to being the most perfect mouse I've ever owned. First, the troublesome, gunkable scroll ball was gone. Now the mouse featured a Multi-Touch surface that allowed me to scroll just by moving my finger across the surface of the mouse. With no moving parts there was nothing to gunk up!
The Apple Mighty Mouse featured two side buttons that allowed you to activate certain features on the Mac, these buttons are not present on the new Apple Magic Mouse. I've heard a few people complaining about this removal of functionality but honestly, I'm glad to see them go. I was constantly pressing by mistake when I would hold the mouse "wrong". They were set to activate the Exposé feature which is also accessible from a keyboard shortcut that I prefer.
The Apple Magic Mouse, as with most other Apple products, is designed to be visually appealing. Its streamlined form factor definitely pretty. It's a little more thin than the Apple Mighty Mouse and this has prompted complaints that it's not a very ergonomic design. I have to admit that after several hours of heavy use the muscles in my hand tend to hurt a little more than when I've used other Mouses (Mice, Meese?) for similar periods of time. It may have just been the hand muscles needing to adjust to being used a new way because I haven't noticed it lately.
Also, you'll need a clean surface. More than once I've had to clean the laser port on the bottom (generally by giving it a good blow) when a piece of lint or desk trash would get stuck and block the laser. This has led to me keeping my desk less cluttered so I don't feel this is too much of a negative.
The one negative that I do want to mention is a problem not exclusive to Apple. It's my complaint with the vast majority of wireless devices; batteries. Years ago I had a wireless mouse (I believe it was from Targus). The best thing about it was that it was rechargeable. When the battery was low I could plug it in via the provided USB cable and continue to use the mouse while it charged. Currently I'm going through two double-A batteries every five weeks or so. I know Apple has recently introduced rechargeable batteries but I already have rechargeable batteries, however I don't want to deal with batteries. The only design difference I would suggest for the Apple Magic Mouse would be take away the double-A batteries and make the mouse a solid unit with rechargeable batteries. Just add a USB port on the mouse that would allow me to use the mouse while it charged. That would, for me, make-up the remaining 10% of perfection and I'd never need another mouse.
Batteries aside, I'd highly recommend the Apple Magic Mouse to any Mac user. It might take you a little while to adjust to holding it "correctly" so as not to give yourself Carpel Tunnel, but if you're using the Apple Mighty Mouse it's well worth upgrading.
