I managed to get a pair from the Apple Store in Broadway in Sydney and have been testing them out for the last 15 mins.
Fit: Fits perfectly and there are no issues of them falling out. It just sat in my ear as I wandered around the house. They almost feel like they're not there cos they're so light.
Charging case: Standard Apple white plastic. Magnetic closure and snaps close very satisfyingly. The AirPods themselves also magnetically snap into their slots.
Sound: They do sound a bit clearer and better than the standard EarPods. I'm no audiophile but I'm very happy with the sound quality.
Connection: Took less than 5 seconds on the iPhone 7 plus. Opened the case and they automatically appeared on the phone screen. Opened my MacBook Pro and they showed up in less than 5 seconds under the bluetooth tab.
Transition between iPhone and MacBook:
Had music playing on the iPhone. Turned on the music on the MacBook and the music in the AirPods automatically stops. MB music plays through the speakers and doesn't automatically play in the AirPods though. You have to physically select AirPods in the bluetooth tab.
Opened the music app on the iPhone and the message "Looks like you're listening music on another device. To resume listening here, just press play". I did and the music from the iPhone came back into the AirPods.
Overall very happy with the purchase. I'm most satisfied with the simple connection and transition, and the fact that they fit perfectly with no risk of falling out.
Happy to take any questions
Some pics here:
https://imgur.com/a/5ktoc