I've had eight sets of headphones since I got my first iPod Touch in '09, and two of those have now been Bluetooth. These XB50BS phones are all you'll need for gym, Starbucks, running, work, anything, and here's why.
The standard is the latest Bluetooth 4.1 w/ 12mm drivers and 4 - 24,000 Hz range. That's immense. The bass is the strongest I've heard on any Bluetooth device and are even lower than some corded sets. They're comparable to the newer Apple headphones for lows, so they definitely have that extra baseline. I can still hear trebles and highs, so the range isn't skewed to the low end. Granted, it's Bluetooth so when you have them paired and not listening to something, you're going to hear a little feedback from the receiver picking up the signal.
When these get paired, turned on, or in sync mode, a female voice will call over telling you what stage you're in. These is convenient as my last Sony set only made beeps at different lengths. I don't believe there's a language feature for this, so it defaults as English. The buttons are on the right side's posterior edge. There's 3 buttons; one is for power/pause/pairing/call receiving. The two other buttons are for track skipping and volume control. Holding down the button for 2 seconds allows you to skip a track, pushing it repeatedly (or once) changes the volume. Obviously these are <- and ->. This is pretty standard, but I did notice I cannot "scrub" a track, i.e. fast forward/rewind during playback. The sides are soft vinyl, and the charging port is also located on the right side.
The ear pieces are becoming even more complex these days. You have SS, S, M, L for silicone nipples, and this set also has two different silicone inserts for pseudo intra-aural stability. They take some used to placing in the ear, but they keep the buds from spinning. This set is the most noninvasive I've had seeing as it's a chord and two earpieces that are relatively innocuous. So you won't have to worry about "popping" the buds out of your ears with the chord inadvertently. Also, because they're silicone buds, ambient sounds go waaaaaay down. I can listen to them in crowded rooms as they phase out a ton of side conversations, even on lower volumes.
I haven't tested for battery life or water resilience, but it's raining right now and they're doing fine. You can't douse them in the pool. Battery life is rated for 8.5 hours, but I never listen to music for that length of time. This set does not come with a nice little polyester pouch to carry them in, and the micro USB charging cable is two feet long. You need your own comp. or USB wall plug to charge them. Sony has so many headphones in circulation that they're trimming the fat on accessories.
I earnestly recommend this set right now. Not only are they an improvement on later models, they're just about everything you'd look for in a convenient package. Great audio, easy interface, physical stability, innocuous, relatively rugged, and of course affordable. Pairing with my Gen V iPod Touch took six seconds. Highly, highly recommended.
Note: I've had these for a month now an I feel nearly the same about them. One note, the chord does catch on the collar of polos and jackets. Also, when switching between paired devices, you usually have to switch manually. It's not a full on re-sync, but it doesn't auto-connect like they would if you just turned them off and back on. Otherwise, excellent quality and worth every cent, but I managed to get mine for 20 bones after sale price, post holiday bump, and BB points!!!!!