The Beats Solo3 headphones are virtually identical in appearance to the Beats Solo2, but the W1 chip in the newer model boosts battery life and simplifies the pairing process with an iPhone 7.
Japanese-language site Macotakara did the comparison, and has examined aesthetics of the new headphones, the W1 chip as it pertains to device pairing, and overall audio performance.
They have discovered that battery life of the Solo3 hits 40 hours, instead of 12 in the Beats Solo2. The gains do not appear to be from a vastly larger battery, as the weight and the volume of the headphones are essentially the same.
The site examined the W1 pairing technology in the new headphones, in conjunction with an iPhone 7. Connection is apparently as simple as Apple claims, with the user only needing to hold down the power button on the headphones to pair with the iPhone, followed by a tap in the iOS 10 pop-up window announcing the presence of the headphones.
Mactakokara does not appear to have done any range testing on the headset.