I purchased these during Amazon Prime Day, I've been using them at the gym and they don't fall out - which is great.
But, it can be temperamental going into mono mode on 1 ear bud when removing from the charging case and some times its as easy as tapping the button on the bud to reconnect them in stereo and other times it seems "glitchy" and the only option is to put them back into the case together and leave them for a few mins - then pull them out together, and they'll usually be synced properly.
The charging case is a great idea, but I've put my earbuds in the case for a week and left it in the car etc - gone to the gym and after 30 minutes I get "low battery" audio warnings so I question how secure the charging connection actually is when there in the case, it certainly feels as if a shake dislodges them.
But my biggest gripe is the signal drops on the earbuds themselves, sometimes it's great other times my music vanishes & fades back in every few minutes, usually once per track and when I check my phone I see no notifications etc that could cause anything like that - I always put it down to it being interference from the gym machines, but I was recently walking through a field after dropping my car off at a garage and my music kept losing signal and fading back in.... I'm positive this is some glitch between earbud signals rather than the signal from my phone as I don't get it on any of my other wireless earphones + my phones either in my pocket or infront of me at the gym.
All in all, I'll be looking for an alternative set of earbuds in the not too distant future, as these have been a disappointment but I love the truly wireless style of earbuds.