Sound
They aren't going to knock your socks off but they're respectable. There's essentially no low end but you can still make out things like an upright bass string being plucked. High end is a little sharp but not so much that it's distracting.
Battery Life
I charged them on my way into work on Tuesday. I've listened to them for a minimum of 4 hours each day over the last 3 days at a volume on my laptop of 20. Whenever I've gone to grab a print out of the printer or made a quick trip to the bathroom I've left them on my desk but didn't turn them off. The couple of times I've left my building or when I've gone to lunch, they have been turned off.
All that said, Windows is showing them at 60% still. Pretty amazing considering their own documentation says they have a 6 hour battery life, but that's at 70% volume.
Bluetooth connection
I've left them on when refilling my water bottle and they've stayed connected over 35 feet away and through a wall. That's more than enough for my uses.
Comfort
While I usually only wear them for about an hour at a time before they're off for one reason or another, I was concerned about them as bit as my son said someone he works with has a pair and said they give him a headache from the pressure. With the way I've used them, thankfully that hasn't been an issue.
Other
Keep in mind that I'm using them in an office setting. I have no idea how any of the above would be affected by using them while riding a bike outside or somewhere noisier but I'd wager that the experience wouldn't be great. In a fairly quiet office where you still need to be present, they've been great.
A co-worker has a pair of bone conduction headphones (a different brand) and he said he needs to have his cranked up to be able to hear them. He tried mine and said they're much better so all of the above is apparently subject to change given the brand. I sent him a link to the mine and he said he's buying a pair tonight.