- Size
- Glass surface, nice to use
- Gestures, e.g. 3-fingers to drag (that's the one I find most useful, you have to enable it), 4-finger swipes for multiple desktops, show desktop, show all windows etc.
Agree that you have to re-train your hand so that you don't try to 'click' with your thumb (which registers as a multitouch gesture and causes all manner of fun) - I've encountered people with that problem. Personally, I could never bear to use lesser trackpads, so my thumb probably didn't get 'trained'.
They're a glass surface? I don't think I've ever noticed that. Again, I don't use the gestures. My HP Envy has pretty similar gestures and I never use them but the two finger scroll. So yeah I'd probably just use a mouse with it.