We've done a lot of tests with the ergonomics of it - even delaying our launch for a month so that we could iterate more because the side-sleeper comfort wasn't up to par. it's smaller and rounder than what you see in the video as we filmed the first half of the video before our final design. ~70% of the people we had sleep with it for an entire night noted that it was comfortable. that number will get even better as we implement the inner silicone layer.
the main difference between using in-ear headphones with comply tips is wires. I've had to used wired for a long time and it was terrible. They'd tangle and get pulled out of my ear. They'd pull my phone out of the charger. I've even had my phone run out of battery in the middle of the night because it got disconnected. When you roll around, wires in bed are not a pleasant experience. :(
Also, the software built in is very different. Normal earphones don't have our user-friendly software that has features designed for sleep. I.e. when an alert sounds on your phone with normal earphones, it sounds in both your headphones and your phone's speaker - waking up others around you. There might be some hacked homebrew way of getting some of Hush's software features on normal earphones but our software makes it easy. :)