When I first heard of the Osmo, I was skeptical. I wasn't sure that a device like that was going to be very useful. After I saw the demo footage, I was blown away and I knew I was going to get one. I didn't know exactly what I was about to get into, but I'll tell you what I've experienced since owning one.
First things first, this thing is amazing and very versatile. I've shot tons of live events with it, shot some of my demo video for my lighting equipment and even a music video. Since i have a bad back, It makes working with a camera on the go very easy and way less painful. I have some shoulder rigs that I use as well and sometimes I can't even stand up straight by the time I'm finished shooting. The best, recent example I can give is the Sick Disguise music video for Armstrong. I used the Osmo for most of the video and it turned out amazing. If you notice, I'm using the camera for all the steady shots and for the shot where I'm circling the band during the performance. If that doesn't tell you that this thing is amazing, I don't know what will.
The downfall of the Osmo is the on-board audio that it captures. When the audio started playing back on the video, I knew right then and there that I could never just use the Osmo for live events, I would need to attach an external microphone to it or use a completely separate recorder all together. It does good when there's no background noise, you'll just hear the motor of the camera balancing as it's recording and the audio will be pretty low on top of that. If you want to use the Osmo for live events or something that really requires the audio to be clear, you'll need to get an external mic. Otherwise, you'll be very disappointed with what it captures. I got lucky since I haven't needed any audio from the camera since I only record off the sound board now. If I ever need to use an external microphone, I would wire shotgun mics or lapel mics, I never use on board camera audio in my final products.
Those are the biggest features from the Osmo that I can tell you. There are tons of video reviews out there for the Osmo if you want to watch those to get detailed information, but these are the 2 most important factors in your purchasing decision. Check out the official music video for Sick Disguise from Armstrong here to get a real life example on how the Osmo can be used. Enjoy :)