I have a set of Aftershokz Titanium. I bought it with the intention to use it while doing chores around the house, watching the baby, or walking around with friends. While it works perfectly for those situations, the SQ is really bad. You get better sound out of those free earbuds you got with your smartphone 7 years ago. For these purposes, any of the Audeze iSine IEMs do a much better job since they produce excellent sound with zero isolation.
However, for situations where you need complete awareness and resistance to wind noise, like cycling or snowboarding, bone conduction might do a better job. I can see the iSine IEMs being quite bad with wind blowing across the shells. Also, I wouldn’t want to get any sweat around an iSine, whereas the Aftershokz are quite sweat-resistant.
Overall, I think bone conduction is an interesting technology, but not suited for audiophiles at all. At best, the sets allow you to have background music while keeping your ears free.