I have the P10 and a LP12 in two different systems. My P10/Apheta 3 is in a system with Klipsch Cornwall IV speakers and Luxman EQ-500 phono stage. My LP12 is in a system with Harbeth M40.1 speakers and a Zesto Andros phono stage. My LP12 has the Radikal power supply, Keel subchassis, Ekos SE tonearm, Akiva MC cartridge.
I've had my LP12 25 year anniversary model for about 24 years and if I were buying it new it would cost almost 3 times the P10. I've had my P10 for about 1-1/2 years but I've never compared it A to B in the same system with the LP12. Before the P10, I had the Rega RP10/Apheta 2 for 4 years. In my opinion, the P10/Apheta 3 is clearly better than the RP10/Apheta 2. If I were starting from scratch and buying a new TT for either system, I would buy the P10/Apheta 3. I think the P10 is a fantastic TT.