From a sound standpoint, as I said, despite the inability to get a tight seal, I thought it performed well for a Bluetooth headphone.
It plays loudly and has relatively clean, aggressive sound that's filled out with rich bass that isn't overpowering, thankfully. That seems to be Beats' MO with its new headphones: scale back the bass a bit while punching up the treble detail. As with the and Solo 2, I wouldn't call this a balanced headphone, but it is more balanced than last-generation Beats headphones.
I spent some time with the headphones in the gym and also did some runs with them outside. In the process, I compared them to Plantronics' BackBeat Fit Bluetooth sports headphones, which cost $70 less. The BackBeat Fits are a little lighter and arguably a bit more comfortable, but both stay on your ears securely and have similar "open" fits (they let some ambient noise in).
I like the sound of the Plantronics, but the Beats do play louder and have a little more bass kick to them. Of course, when you're running around outside with lots of ambient noise around you, it's not the ideal listening venue, and I'm just looking for headphones that are comfortable and sound decent.
For fans of Jaybirds X headphones, I like those as well, but they're all about getting a tight seal and jamming the tips into your ears (it can be hard to maintain a tight seal). I don't find the Jaybirds as comfortable as either the Plantronics or the Beats.
In-ear wireless sports headphones are hard to do right, and Beats has gotten it mostly right with the Powerbeats2 Wireless. It combine strong sound (except in noisy environments) with a design that should comfortably fit most people. That makes it a pretty safe pick in a category (wireless earphones in particular) that doesn't have a lot safe picks.
The only problem, of course, is that they're expensive. At $200, you'd like to see an automatic shutoff feature and perhaps full waterproofing rather than just sweatproofing. On the plus side, the headphone is firmware upgradeable, which should help keep them up to date as new smartphones and Bluetooth chips arrive (the headphones seem pretty durable, but I only tested them for a couple of weeks, so I can't tell you whether they'll hold up for years or not).
In the end, I don't have any problem recommending the Beats Powerbeats2 Wireless, particularly if you're looking for a workout headphone. You just have to be comfortable paying a little extra for the Beats brand -- or as I like to call it, the LeBron Tax.
It's a very good Bluetooth headphone; it should just cost about $50 less.