For years, I used a Logitech mouse, as it fit my hand. It's still connected now to my MacBook Pro. The iMac I bought came with a Magic Mouse, and I added the new Magic Trackpad. Before I added the trackpad, the mouse was just fine. I was pleased with the way it worked, the way I could move my hand around on top of it, or move the whole mouse. Very different, but also very powerful. Being able to instantly zoom in on the screen image was a wonderful bonus - and after playing around with the other things it can do, I think it's great. I never got serious about replacing it with a Logitech mouse, but I'm getting pretty serious about buying another Magic Mouse for my MacBook.
The only "unusual" things started when I hooked up the Magic Trackpad. With the trackpad, you swipe one way to get to the <delete> button, and the other to get to the <unread> button. With the mouse, those things start to appear, but I'm not sure how to program the mouse to do it the way the trackpad does.
The Magic Mouse can do SO many things. It's confusing at first to get used to all of them, but now that I've gotten used to it, the Logitech mouse seems too.... basic.
Update - by using two fingers, and the Magic Mouse, I can now swipe a message one way or another to see the unread or the delete choice. The only one I ever use is delete, but now it's working just fine!