I'm not sure that any extra weight makes much difference - isn't the standard suspension just specified and tuned to take account of the weight. Must admit though that I'm weighing up the pros and cons of air.
I guess the main pro is that you might expect a smoother ride (though I'd also expect the standard suspension to be pretty good and we won't know in more detail until test-drive cars or detailed reviews start to become available). Effects might also be more pronounced of course on 22" wheels compared to smaller.
The other pro seems to be the ability to change the ride height. (-40mm and +50mm did I hear somewhere? Though quite often air cars are set up with different ride heights to standard and so it's tricky to compare until full specs are available.) So the low height might be good for a few extra miles of range on motorway cruises, while the high ride height for off-roading or fording.
Obvious extra cost plus more things to go wrong.
People sometimes complain that air cars are too floaty and might encourage car sickness for anyone that's that way inclined.