Haven't heard the BT version but the regular 1R is pretty much the opposite of the P7. Yes they both have pretty good soundstage for closed headphones, but the sound signatures are so different.
Treble - both have good extension but the 1R has a very laid back top end, so overall it sounds very warm, even dark by some standards. P7 has lots of treble energy, very crisp sounding without being harsh. Treble resolution is amazing.
Mids - 1R has very warm, lush, rich mids. P7 is rather dry and lean in the lower mids.
Bass - 1R has a midbass hump which masks the subbass. P7 has emphasized bass but the emphasis is lower compared to the 1R (much more subwoofer-like) and the leaner lower mids makes it sound cleaner and less boomy.
10-point scale, an overall assessment of what sound would you put?
The 1R is very technically competent but sound signature wise I would only give them 7/10. P7 is like 9.5/10. However if you EQ both to have the same sound signature they would sound very similar in terms of detail, speed, soundstage etc.