The Airism don't lose their shape over the course of the day.
The 100% cotton ones: You start your day wearing boxer briefs, but by the end of the day you're wearing regular boxers. They get kinda baggy.
Don't get me wrong, they're not the terrible product that the seamless ones are, but the airism are worth the extra $6 for me personally.
The seamless boxer briefs are fucking AWFUL, it's true.
The Airism ones are best. The regular fit cotton ones are decent, but if you wear pants that are slim through the thighs, you will feel them in there, and they'll stretch and get droopy if doing any physical activity. Just get the Airism ones and be done with it.