Thanks for the welcome.Welcome!
The Air actually has more cargo space, and a much, much bigger frunk. The trunk works great, just requires a little Tetris-ing. The benefits of the trunk over the hatchback are very obvious in ride quality, imho. It was a very intentional change from the Model S, for rigidity.
My kids will tell you that my spatial awareness is pretty good and they've marveled at my Tetris-like abilities loading vehicles. Comes in handy when moving them in/between/out of apartments, etc.
My concern is not total storage/cargo space, but the ability to load oversize objects. No longer owning a minivan or any form of SUV or pick-up truck like vehicle, I've used my Model S to transport some pretty bulky items. With the back seats folded down and the height of the hatch back opening, I've been able to load some items which I question whether I could get them into the trunk. That's my concern but also why I need to see one in the flesh before making any firm judgement/purchase decision.