What will this sacrify compared to a MacBook air?
- 1 UBS C port (remains to see if there is magsafe or not, or if it's like the iPad)
- Thunderbolt
- likely base RAM will be lower (8 or 12GB) with the option to upgrade to 16, but not more
- battery size, probably a smaller batter to avoid this having longer battery life than the air.
- slightly smaller screen
- storage options will probably cap at 1TB (also possibly slower storage too)
- long term support (may be supported 1-2 years less than the regular M series Macs, just like the iPad A series is supported for 5 years of OS updates instead of 7 for the air/pro)
- webcam quality
- charger in the box?
As for weight, it will probably be lighter than the air but definitely not as light as the 12" MacBook.