I would skip the air 3 because of the white spot risks associated with the 10.5 model....
The air gap is important only if you use the pencil regularly, if you do, it's quite annoying, it's like having a think glass under the pencil. For use with fingers it's fine.
Air 4 has some very nice perks like usb C and pencil 2, which is much nicer.
As for true tone, it's not a matter of brightness, but of colors. For me the main advantage is that it gives me warmer colors. For ipads that don't have it, I simply put warmer colors all day via night shift to obtain a similar effect. It's not variable like true tone, but I like warmer colors (but not too warm, I try to set it at the same level as true tone) all day...
The air gap is important only if you use the pencil regularly, if you do, it's quite annoying, it's like having a think glass under the pencil. For use with fingers it's fine.
Air 4 has some very nice perks like usb C and pencil 2, which is much nicer.
As for true tone, it's not a matter of brightness, but of colors. For me the main advantage is that it gives me warmer colors. For ipads that don't have it, I simply put warmer colors all day via night shift to obtain a similar effect. It's not variable like true tone, but I like warmer colors (but not too warm, I try to set it at the same level as true tone) all day...