I've had these for about three weeks now, and they're pretty good. They're well-built and designed fantastically, the way they work with the charging case is great, and they don't necessarily sound bad. Compared to Earpods, they have ever-so-slightly less definition in the highs and mids leading to a slightly muddier overall sound, but it's a comparison you'd only be able to make for the first 24 hours or if you're switching back and forth between the two. They're perfectly acceptable, almost bordering on good, and will sound great to most people. If you're an audiophile that uses mid- to high-end headphones while at home or sitting at a desk for work, however, you'll be disappointed by their small-ish range, apparent emphasis on lows, and lack of soundstage.
FIT, CONNECTIVITY AND BATTERY LIFE
As for fit, these stay in my ear better than Earpods because there's no cable constantly pulling them down and out of my ears, a problem that made wired Earpods pretty much unusable for me. I've never tried running with Airpods, but I can confirm that shaking my head around violently wasn't enough to cause them to fall out, so take that for what it's worth. Pairing is also just as simple as people make it out to be, but it's easy to overlook just how seriously quick these connect to your phone. Because they start to connect as soon as you open the case, by the time you take even one out and put it in your ear, it's connected to your phone and ready to play music. It's almost scary how fast they are. Five hours of battery may not seem like a lot, but unless you're on a marathon work session or flying across the entire continental United States, five really is a reasonable number. Combined with the fact that they quickly charge whenever they're in their case, it'll seem like they're never dead.
I've noticed two notable issues, the most glaring for me being that they're hard plastic and will hurt my ears after serious prolonged use. This will vary from person to person, and I do have sensitive ears based on other headphone's I've used, so your mileage may vary. The other issue that's more of an annoyance is their extreme lack of noise isolation. I'd say they're even a little bit worse than Earpods, so you'll really have to turn your music up to drown out external noises if you're somewhere busy. I gave them a 3/10, but they're closer to a 2.5/10.
All of this is to say that their best use case is...any situation where you'd use Earpods. That might sound obvious, but it's true; walking, biking, skating, on public transportation, possibly running, for sharing music with a friend, anything like that. Normally, that wouldn't justify the $159 ($172 after sales tax, by the way) price tag, but add the wireless connectivity, great battery life, and seamless connection and integration with your Apple devices, and they just manage to be worth the money (for me, at least). Having something as small, portable, and inconspicuous as these while being completely free of wires is one of the most liberating experience you'll have if you've never owned wireless headphones before.