Updated review: Lowering stars by one. I love the way theses B&O Play headphones sound. I love how comfortable they are. Easy to pair. Nice sleek design. All of that. They are amazing in all areas but one: SO frustrating that they do not stay on unless you are sitting or walking about without moving around your head. If you want to do anything with these on, like workout or wash your car or anything that you have to move your head a lot or bed down, off they slide. Frustrating! My other headphones that cost less than these stayed put while I jumped around doing aerobics and other exercises, why can’t these? I have to lower my stars to 3 because I don’t understand this design flaw on what should be really great headphones.—————First off, I recommend you download the app (as they indicate) and use the instruction there since the instructions included in the box are pretty useless (unless you know what you are doing and if you do then you won’t care about instructions). Because I spent some frustrating moments ready to toss these earphones across the room—I was poking this button, sliding that one. It wasn’t pairing; it wasn’t playing; it wasn’t being nice at all—all because I was doing the wrong things and confusing the heck out of it; ha..Once I opened the instructions on the app, everything was clear, and I knew what I’d done wrong. Yay! As well, I watched the short video provided on the Amazon page.My headphones needed to be fully charged and I let them charge overnight. 30 hours is pretty danged amazing—I always cut that by about 1/2 to 3/4 since products rarely last as long as indicated; so even if I cut that in half, 15 hours is still great. I’m curious to see just how long they will last before I have to recharge.Comfort & Fit:These B&O are comfortable enough, though I am surprised at how thick the head band is. The ear parts are super soft and comfy. However, one of the reasons for the 4 stars versus 5 stars (see below for other reason) is because they slide around. I was really surprised at that. I have a pair of way cheaper BlueAnt headphones that stay on no matter what I do—dance, jump around, HIT workouts. But these I am going to have a hard time doing my HIT workouts because they aren’t going to want to stay put. I’m hoping when I’m doing jumping jacks or burpees that somehow I can adjust them to stay put, and if I do on my next workout, I will come back to update.Sound:The music comes through clear and crisp. Through the app, you can alter the sound to your liking: more bass, more treble, etc, just by either clicking the pre-selected items (warm, energetic, etc) or by moving the circle around to pick what you like best. This is a great feature to use for whatever you are using your headphones for to optimize your sound experience. As well, with the app, you can pause, advance to next song, etc. I’m happy with the crisp sound quality. I did fumble around a bit trying to find that feature and actually found it by accident.The sound quality is great for phone calls as well. A friend called me and I had the headphones put away. I asked him to call back so I could use the headphones but when I picked them up while telling him that, I could already hear him on them. I must have had them still on and they were in the mode to answer without me pushing a button: they do pause when you remove them and start again when you put them back on, which is awesome! He heard me very clear and I could hear him just as clear. I fiddled with the ANS and Transparancy button and there was some difference on his end especially. If I had been listening to music when he called, I’d just have had to press the right middle button once to answer and pause the music.Features & etc:I’m still trying things out—like the transparancy and the noise cancellation. While I had the headphones on, I began the video to learn a little more about B&O H8i and by sliding the transparancy (I think; still learning), I was able to hear the video clearly; sliding it again made it muffled. The app has the sound quality feature mentioned above.The B&O Play comes with the headphones of course, USB charging cord, an outlet adapter, a cord if you don’t want to or can’t use the Bluetooth feature, useless instruction booklet, and a soft cloth bag.As for the soft cloth bag to keep everything in: this is another reason for the 4 stars instead of 5 (other than the slipping around of the headphones). My BlueAnt came with a handy case to keep everything in and secured. This B&O is $399 (at time of this review) and they couldn’t spring for a more sturdy case to keep everything in and secured? For that much money, I would think they’d want to ensure that the headphones were very much protected because I sure want to protect them in something more than a cloth bag—it’s like, seriously? A cloth bag? A cloth bag is a weak point.Look:These are good-looking headphones. Sleek, modern, but simple.All in all, I’m super happy with them. If they were more secure on my head and came with a case instead of a bag, I’d have given these 5 stars.