Got my Air on Friday. Got the 128GB LTE via Singapore.
The lightness is overrated (to me). Yes, it's lighter, but it's not like "WOW SO LIGHT!" (if you know what I mean). Not that much difference la (but all the reviews online seem to sing a different song, so maybe you want to hold one before you decide).
I came from an iPad 3, so the main thing for me is the speed. I kept my iPad 3 on 5.1 (JBed), but iOS 7 on the iPad Air absolutely flies. No lag at all, when previously I would have experienced some lag on the iPad 3. And I love iOS 7 (first experience with it).
The Smart Case is excellent. Really high quality, almost (haha) worth the money.
All in all, it's a great device, but if the lightness is your primary reason to upgrade, honestly it's not worth it for me. But if you want to "upgrade" from iPad 3 or 4 to the new iPad Mini Retina, now that's another story.
My two cents.

If anyone has any questions feel free to ask.
This post has been edited by DeaDLocK: Nov 4 2013, 02:39 AM