Probably depends on your usage, what car you're coming from, and what you're looking for. If you're looking for comfort or are coming from a high-end luxury vehicle, I can see the air being a huge selling point. I drove a P85+/air, a S85/coil, and an S60/air, and loved how communicative the S85/coil's suspension was compared to the others. I didn't mind the ride quality hit, because my current car is fast, raw, noisy, and bumpy, and I kind of like it like that. I'm not worried about driveway curbs, because I don't have any, and my current car is low so I'm already trained to be careful about clearance when out and about.
I also went against conventional wisdom and got the 19"s. Despite what you would think, they have a larger contact patch (more rubber on the road) than the 21"s. The main problem, IMO, is that they're saddled with touring all-season rubber. With better rubber I'd expect launches to match 21"s, though the contact patch advantage will be offset in the corners with the larger sidewalls. In exchange you have less concern about wheel damage and, IMO, a lighter, better-looking wheel.
So as you can see, my priority was Performance over most of the other options.
What I'm getting at is, don't listen to what other people say are must-haves. They're not you, they don't know what you're looking for, and at least in some cases are attempting to justify the options they've purchased as being the ideal configuration.
That includes me. Don't listen to me, either. :wink: