A while ago I started to experiment with Google Cardboard and noticed a strange problem with my Sony Xperia Z3 Compact: as soon as you connect a headphone the view will jump back to the initial position in some Cardboard applications. This problem is also documented at Github and seems to be specific for the Unity SDK for Cardboard. A solution is not available yet even beginning of 2017. But these effects do not occur when using a Bluetooth headset.
This has basically fulfilled its purpose, but was rather uncomfortable during longer sessions due to its shape, since it rests only on the ears and does not enclose them. As a better alternative, I bought a Pioneer SE-MS7BT in the black version, which combines classic design elements with modern technology. In addition to the black version, there are also other versions with silver earcups or brown upholstery.