A year!?
I got rid of mine within the first four months, haha.
My first one broke within a month (Scroll ball) then the replacement suffered the same fate.
Now, I know I'm not the cleanest of people (my hobbies involve messy substances on my hands- No, it's not what you're thinking

) but this is a common issue, so I knew that all mighty mice I would get would end the same fate, and eventually Apple would become bankrupt because of me! (lol xD)
I did the same thing as the OP and bought an MX Revolution. I've always been a fan of Logitech mice.
Whoever said you don't quality mice with PCs is wrong. My PC (a cheap one) came with a sturdy little Logitech mouse. Just a plain one with no fancy features but it was very durable and, to some extent, better than my MX Revolution. If it wasn't for the fact that OS X begs for multiple buttoned mice then I would use it with my iMac.
I've noticed that my time on my iMac is a lot more enjoyable with my MX Revolution. I don't have to keep wiping dirt and grim off my mouse every five seconds, I can scroll downwards (And sideways because the Logitech MX Revolution can do that) and I don't have wrist pains anymore. Plus I have the same features as the might mouse. A nice scroll wheel (although my messiness has caused it to kinda snag a bit) which goes in every direction, a button for Dashboard in the middle, an expose button on the side and my MX Revolution is wireless, unlike my Mighty Mouse was (Didn't want the wireless keyboard because I like having the number pad for Sibelius)
If I were to get a Macbook, which I hope to do, I'll probably get a bluetooth Logitech one. Logitech is my favourite Mouse Maker. Shame they didn't have a Bluetooth MX Revolution out in the public when I was to buy mine... Ah well.