The Mavic Pro was - is - a phenomenal quadcopter. Easily human-portable, 4k video and good stills, good battery life, speed, manouverability and systems redundancy, and affordable.
Moving forwards a year, DJI have compressed the Mavic Pro (or most of it, anyway) into the Mavic Air. The Mavic Air has a slightly slower top speed, slightly shorter battery life, less systems redundancy, but it's also about half the weight and size. It also has a better camera (100Mb/s compared to the 60Mb/s of the Pro), and is a bit cheaper.
- deploys faster
- greatly improved gimbal reliablity
- greatly improved gimbal cover
- one can put black stickers on the red one, and make it look like a ladybird
- fancy automated video modes and hand controls, if those are your thing (I haven't tried them)
- the noise is more annoying, especially when compared with the quieter propellers on the Pro: high-picthed and buzzy, on a still night, at 100m AMSL, the Pro's sound is mostly lost, but the Air is still clearly audible
- in 'normal' (non-sport) flight modes, it's noticably slower: flicking the switch to sport mode brings it up to speed, but at a signficant battery cost
- it uses WiFi for R/C: I've found this, in an urban area, to be less stable then the system use in the Pro (solid overall though, and no issues since 1.04 of the firmware)