As we said in the hands-on, the mouse has one piece of clear white plastic on the top, curved, like a Dove bar. It has both right and left clicks, like the Mighty Mouse, but differentiates itself from other mice with its touch-sensitive scrolling and two-fingered gestures. That's the big selling feature (other than the fact that it is a beautiful-looking mouse).
As a mouse
The Magic Mouse is a very, very pretty mouse—something you wouldn't feel like you had to hide when not in use—and looks different enough from other mice that people will ask who made it, before awkwardly mumbling a nevermind as they spot the grey Apple logo.
Compared to ergonomic mice, the Magic Mouse is really low and aerodynamic, which means it doesn't contour to your hand and doesn't give the sensation that the mouse is a part of your hand, like Logitech mice tend to. But it is Bluetooth, so you don't need an extra dongle, and it's powered by two AA batteries, which get up to four months of use per charge, according to Apple.
Physically moving the mouse and mousing is fine and smooth, since there are two plastic bars on the mouse's underside that minimise contact with whatever surface you're on.
As for tracking, it's a pretty standard laser technology that tracks decently on most surfaces, including jeans and chairs. Still, the Magic Mouse doesn't have the crazy tracking ability that Logitech's MX mice just introduced — so it can't track on glass, and it can't track on glossy surfaces like the 13-inch MacBook.
The one thing Apple did completely right in the Magic Mouse was the touch scrolling. It's fluid, natural and works with any amount of fingers on over 75 per cent of the mouse surface (all the way down to the Apple logo). Flicking up and down gets you up and down web pages fast, as long as you have "momentum" turned on in the settings. Turn it off and you get fine-grained 1:1 scrolling — good if you want to slowly navigate through a PDF doc.
You can also click with one finger and scroll with another, letting you highlight blocks of text like you would on a normal scrolling mouse. On the whole, there's no major piece of scrolling functionality (other than a middle click) that you lose transitioning from a standard scroll wheel to this touch-sensitive solution. You just get the ability to scroll in 360 degrees as a bonus.
The only flaw is that you sometimes activate the left (or right) click when you're scrolling too emphatically. I suspect this is just something you'll get used to over time, but it can be annoying when you're trying to scroll and you navigate somewhere else instead.
Using two finger swiping to navigate web pages, on the other hand, is a bit more awkward. You'll need to pinch the mouse on the sides with your thumb and fourth/pinkie finger while you're scrolling, forcing you to make a painful eagle claw all the time.
What it can't do
As good as the swiping gestures are, they're limited in what you can actually accomplish with them. You can't use more than three fingers at a time, because you won't have enough fingers left to hold the mouse. There's also no option for touch-sensitive clicking, like in trackpads, something that would have been cool to have just as a bonus. You also can't tell which side is up just from touch until you click down and feel nothing happen.
So far the Magic Mouse is only compatible with the iMacs that they ship with, but will get broad support soon.
It also can't manage to stay free from scratches, similar to white MacBooks that also get scratched very easily. But the blemishes don't interfere with the mouse's functionality — it's just painful to watch any new product lose its pristine finish so quickly.
Is this the best mouse Apple has ever made?
Yeah, it is. The Magic Mouse is much better than the Mighty Mouse, which people hated, and might actually be good enough that non-Mac users might want to pick it up as well, supposing that they don't really care about ergonomics. Since it fills the gap between a tiny travel mouse and a full sized desktop mouse, the Magic is in a good position to grab users on both ends.
It looks very nice
Touch scrolling works well
Swiping is less comfortable
Not very ergonomic