Whilst I'm not discounting the testimonials here about their resistance to sweat etc, I'll be interested to see if they still hold up after 6+ months of hard gym use.
Been using BT earphones since 2011, very regular gym goer and runner. I'd say my sweat output is average.
I've had several pairs of not-cheapo BT earphones go bad. Jaybird X2's, a couple of Jabras can't recall the exact name of, some Sony ones specifically for gym usage. All tended to fail after about 12-15 months.
The only ones I've got 2+ years life out of (and still working) are my Plantronic Backbeat Go2's, still going strong.
Basically, regardless of what those stress testing YouTube videos say, and people saying how great they work after 1 month (which is nothing), I thinks it's way too early judge.
Fortunately, the gym and running are the one and only place I prefer my BackBeat Go2's. Noise isolation is essential, as are the buttons on the wire, they beat double tapping or using the Watch (which I have and use). For all other applications I love my AirPods.