I had the very first version of AfterSHOKZ, but unfortunately, I broke them. I tried some Sony headphones, and most recently I had a pair for swimming that went behind the ears with MP3 playback – they lasted 7 years. So, after about 10+ years, with a bit of trepidation and a guilty conscience (because it's a hell of a lot of money for a silly pair of headphones), I bought Shokz again – this time the version for swimming. Compared to the original version, they definitely have better (more flexible) materials and are significantly smaller overall.
I use the headphones every day – for sport (cycling, running, swimming), for walks with the dog, for physical work (like when I'm digging a trench or chopping wood), and for work at the computer.
They don't hurt behind the ears and they sit firmly.
The open-ear design is an advantage (you can hear your surroundings) but also a disadvantage – a passing car will reliably drown anything out. I haven't tried them on a train/the tube yet, but from my experience with the first version, I know it's not great, the surrounding noise is just too loud. On the bike, however, the wind noise wasn't a major issue and listening was perfectly fine.
But when I put earplugs in (a pair is included, but I use my own), they were completely fine to use while cutting with a chainsaw.
They worked perfectly when swimming in the water – it was as if they got louder. They didn't fall off, even during more vigorous strokes.
The battery life is fantastic compared to the Sonys – the 8–9h is realistic.
When I'm running, I can hear what's going on around me – that's their absolute best feature. I can even hear my dog breathing, let alone a car on the road in the distance. It feels as if the sound is coming from your surroundings, not from the headphones.
The only downside is that contraption for charging and uploading files – I have to be careful with it and I'm hoping the cable has a long life. It's designed nicely (with a magnet), but it mustn't break. That's probably the only design complaint I would have.
Oh, and the app is surprisingly usable, I definitely recommend installing it.
So yeah, if you're hesitant to shell out that much money for headphones, don't be, they're really nice. They're not for audiophiles, that's obvious, but for casual listening + podcasts, they're perfect.