Does anyone have custom-made earbuds?

I am a writer working on a story for a well-known newspaper. I would like to interview some audiophiles about their experiences with custom earbuds that fit directly in the ear canal. Ultimate Ears, Westone Labs, Radio Partner, Sensaphonics, etc. --- all brands welcome. I'd love to hear the good and the bad.
Please feel free to contact me via e-mail.
Thank you.