The P5 wireless is excellent when you want something small and good looking. The sound signature is more 'fun' , upbeat like than the qc35. Not as composed, less seperation between instruments and not as neutral as the qc35, though.
The qc35 makes a real difference when you're commuting by train, plane or have to cope with a noisy background when listening. The sound signature is very neutral, composed, with a lot of seperation between instruments with the bass slightly more than neutral.
The only way to know is to listen to them for yourself, really. Its like I describe how a burger tastes. You have to taste it yourself to judge. The best we can do is recommend a few options when you say what your requirements are. Ie for commuting, during sports, in your home by yourself, in your home whilst others are around etc.