I've had these about a month now. I got them for $48 at my local AT&T store and for the first few days had I had time I would have returned them because I was very unhappy with the fit and sound quality until Google searching and finding more about them and how they're meant to work best.
They don't fit in the ear or on the ear, kinda sorta both yet neither. They don't hang on the back of the neck but yet they do. Read on
If you've ever used a set of LG Tones you're probably familiar with how they fit inside the ear and hang on your shoulder and neck. That's how I thought the Circles were supposed to work and found them to not be comfortable at all when in that mindset. First the in/not in ear part. The buds go almost inside your ear but a little nub rests against your outer ear, keeping them from going deeply inside. This, at first, is very disconcerting if you're, like me, used to in ear. They feel like they're going to pop out if you move your neck the slightest bit but once getting the correct sized buds they do indeed stay put no matter how quickly and strongly I turn my head side to side, up and down or combination of them. They do move a little and don't feel like ear plugs while at the same time they do block much residual sound around, making them not a good idea for driving if you care about hearing what's going on around you besides music.
Now the fit on the neck. As I mentioned they differ from the Tones in how they sit on the neck. If you don't use the included neck band the weight is mostly on the back of the neck vs the Tones being mostly on the shoulder area. I found this to be quite annoying do I grabbed the medium and large bands, found the medium too tight at first, large to wobbly. After a few days the medium stretched to where it's snug without feeling right and I really don't feel the unit on my neck at all anymore unless I'm really paying attention to it.
Why Circles? One thing they work with Samsung phones AND like any other Bluetooth earphones on non Samsung phones. The difference is with a Samsung device and the Gear app (same one as for Gear 1 - S) you not only get a built in music equalizer system but also notifications can be read through your headset , such as your texts read to you, notes you get notified about, calendar events, etc. You choose which to receive, just like a watch only vocal instead of visual. You also get a really neat feature where to end a call just tap the buds together at their magnets to end a call and if they're hanging around your neck, pulling them apart will answer your phone call. Works the same for pause/play of music. Voice accept or reject is another user setable function.
Volume is raised or lowered by sliding your finger along the front of the touch sensitive right ear bud just below the answer/end/play/pause/double tap to skip track button.
I'm getting about 7-8 hours of music playback between charges. They are touted as being "water resistant" , unlike the Tones many use, but I don't know how much they really will shed. Everything is either sealed or , like the charging port, has a cover .
The sound quality is VERY dependent on getting the right sized ear buds but it, like everybody else, comes with 3 sizes from small to large. I found even the large to be a bit too loose fitting so I put one of my daughter's small hair bands behind each side because they aren't too small, they're too soft and the fix I did makes them less squishy, stopping the feeling they are about to fall out. Anyway, if they are fitted correctly the entire range of sound is very natural and nice sounding. Deep basses can practically be felt down to the bones without being boomy. Vocals sound crisp without "s" sounding like the singer has a lisp or other speech impediment. Cymbals sound clear and sharp without being shrill and overbearing. I've also found , volume being independent of each other, having the phone half way up and the Circle anymore than 1/3 up to be too loud for me. I keep the phone about 1/4 up so I can have more flexibility with volume when listening to music on the Note4. On the S I keep the volume about 1/2- 2/3 as its music player doesn't have a gain control like Power Amp on the phone.
When you get a call or notification it vibrates before ringing/speaking and the vibration, not user setable, is practically a massage on my neck. Almost makes me want to send myself several texts after a stressful day
As a regular set of Bluetooth headphones they are pretty nice and a great value at the price I got mine at but pairing them with my Note4 and S watch is pretty much a trifecta of gadgets in that I can do things with the trio paired that I couldn't do with my Tones. If I'm out fishing or kayaking I don't want to look at my watch and sure will not remove the phone from my dry bag to check a message or answer a call. It also makes a nice standalone pair with the S when I leave the phone at home.