Have heard it to be exceptionally good personally. The guy was joyous with how well it superseded his Mighty Mouse.
I have hit three Apple Stores in India to lookout for one. Haven't had a chance to lay hands on one before deciding to get one for myself. But there's also the fact that apple's trackpads are large and good enough to never need a mouse, unless you really want one. Head and heart decision situation. Will pick as soon as it's on some shelf nearby.