I've been using these earbuds for about a week and wanted to leave a review.
TL;DR: Overall, these are a good value. Decent battery life, pretty good sound as long as they fit just right, lightweight, easy to use, good call quality, occasionally have some sound flickering issues. Due to the sound issues, I'd give these 3.5 out of 5 stars. Rounding up to 4.
Battery Life: When I first got them I made sure to charge them completely. I never used them until they died, but I one time I used them for about 4 consecutive hours or so while listening to an audio book and didn't have any issues. I didn't keep close track of how long they lasted before I had to recharge the case for the first time, but I got at least 12 hours, maybe more.
Sound Quality: This was a tough area for me. Since I'm not an audiophile, the sound was fine for me most of the time. My main complaint would be that when the positioning of the earbuds was a little off, the bass got pretty weak and they sounded a little tinny. When I get the positioning just right in my ear, the quality is great, with decent response in all frequencies. Depending on how they fit in your ears, you might notice the same thing. I noticed that the volume had the same issue; if the earbuds were in the right position, volume was great, otherwise they were a little quiet and I had to adjust the volume a little louder than I thought was normal.
Form Factor: I love the size and fit of these. For me, they stay in my ear very well and didn't slip out at all. I'm not a runner, so I can't say if they'd stay in during a hard run, but while taking brisk 30 minute walks with the dog through my neighborhood they stayed in very well. I imagine they'd be fine for most workouts. They're very lightweight and the case is also small and easy to slip into a pocket. They secure themselves inside the case magnetically which is cool.
Multi-Function Button: Instead of a physical button, these are touch sensitive, which is nice. I didn't try out all of the functions, but I noticed that they can increase/decease volume with a single tap on the right/left earbud, and that wasn't mentioned in the manual. The only other function I really used was pause/unpause with a double tap on the right earbud. In general the touch sensitivity was adequate, but sometimes I ended up turning up the volume when trying to pause because it only registered a single tap. Not a dealbreaker, but mildly annoying.
Call Quality: I only tried out a phone call once. I talked to my wife for about five minutes while walking the dog and she said that she could hear me very well. I had no problem hearing her either. I don't know if the mic has much noise canceling ability for working in noisy situations, but for me it worked great.
Connectivity: Pairing was easy. Take them out of the case and they immediately start pairing. My complaint here is that they sometimes seemed to briefly lose sync with each other. The sound would flicker quickly in one or both ears, then come back normally. The problem was worse when out walking, and rarely happened when I was wearing them around the house. This isn't a dealbreaker for me, but it was a little annoying.