I think if you get into the habit of always returning them to the case when removed from your ear, the likelihood of one getting lost will be the same as any pair of earbuds. And not having to hassle with a tangled cord will be a godsend. Also, for me at least, I can't remember the last time an earbud just fell out of my ear from moving around to much or running. If it ever has been ejected, its because the cord got caught on something and pulled it out. Although it's subjective, I do recall one reviewer say they were louder and had more bass than the standard Apple Earbuds, but unfortunately, i can't recall which at the moment. The final aspect I'm looking forward to is the ease of moving the BT connection between devices, what with disconnecting and reconnecting, it's cumbersome and doesn't always happen without a glitch.
What I'm not looking forward to is losing physical controls on the earbuds themselves. I like to be able to stop the audio or adjust the volume easily, particularly when you suddenly need to talk to someone. I'm also fearful that when the Airpods do get released, it will be similar to the pencil and availability will be quite constrained, the options being to order on-line with a long shipping delay, or constantly checking your local Apple Stores for availability and purchasing for in-store pickup. I doubt Apple will do a pre-order for an accessory. Regardless, I'm definitely looking forward to trying them out and very appreciative of the two-week refund period. If they turn out to be unacceptable, I'll check out the BeatsX next.