The default Apple headphones that come with the iPhones never fit in my ears properly, so I've assumed traditional Airpods don't either. They should make dummy versions of the new ones so they can be tried out.
Go in to the Apple Store after release, they usually have models available for trying them out. They keep em stashed away in the drawers of those big tables, and use alcohol wipes to clean them before you try em on. I didn't know this until I recently went in to look at the Powerbeats and one of the employees asked if I wanted to try them before buying. Good thing I did, they didn't fit my ear canal comfortably.
