Summary: I have to take this mouse to the apple store every couple of months to get it cleaned out. I've had to replace it once already because the genius bar guys couldn't fix it (thank goodness for apple care!). When it works, this is a really good mouse, but it clogs far too easily, making scrolling up and down (sometimes side-to-side as well) very very hard, sometimes you can't do it at all. I'm taking it to get cleaned yet again, because it's once more failed to keep clean.
Summary: My mouse came with my brand new swanky iMac that I bought last March. Unfortunately over the past 6 months, the scroll wheel has got progressively worse. After frantically rubbing on the scroll-wheel with my sleeve hundreds of times to try to get it to work, it just doesn't work anymore. Side scrolling still works perfectly, but general up and down scrolling does not.
Summary: Okay, the mighty mouse looks pretty neat next to your mac, all matching, but in reality- don't bother. It's okay for a while with it's one button, but the roller is terrible. I started having problems after just a few months and it became progressively worse over the following month- sometimes the roller not working, sometimes flitting on and off, and the button occasionally sticking despite following advice to clean it, leaving me frustrated with it.
Summary: Really disappointed with this mouse. It has only lasted 3 months. the trackball does not scroll up. Very surprised on how poor and robust this product is. Very expensive product and poorly built.