It’s been a year and a half since I tried them side by side but I never liked the P7, the sound was too narrow and just didn’t do it for me. It was a quick and very easy decision between the two. So I’d say definitely a worthwhile upgrade. I do love the sound of the PX but they do have their issues with comfort, seal and auto on/off wear sensors. If anyone who wears glasses while wearing their headphones is considering buying PX then I’d recommend they forget it.
No - genuinely no.
For my best music listening experience I use the Oppo DAC HA2se and PM-3. I’ve found above that price level my ears can’t tell the difference......
For my usages I can’t choose an overall winner. The PX i use for music. QC35 and XM3 for in flight use and the Beats for watching TV / films late at night.
Like yourself I own all three. My experience with fit was good to begin with but after stretching the headband a bit they ve become my preferred option. Having said this while they are the best sounding from the lot, they still struggle against most decent open back headphones, so unless you really need the noise canceling or the wireless connection avoid the segment all together.