Recently completed my week with the PM-3. My thanks to OPPO and Jiffy Squid for making this program possible. Happy to say I now own the PM-3 and the PM-1. As you will read below, I am thoroughly convinced of the PM-3's superiority over the other referenced headphones, this is my opinion/experience only with my ears and my equipment. This PM-3 trial was with Schiit tube amps only. Short story: Within the first day I become so attached to the PM-3 that in the following week I only listened to the PM-3. The realistic tonal balance, the full and articulate bass, the incredible detail in the mids, and the lack of distracting treble peaks, make this a super enjoyable and comfortable headphone. At the end of the week I did do some comparison listening with the Senn HD650/600, the AKG K7XX, and the Philips X2/27. The comparison listening did not last long, the PM-3 is a clear upgrade to all of these. And this is despite the fact that the PM-3 is a closed phone. Very impressive. Additional notes: Except for the last day, all of my listening was with the Schiit Lyr1 fed by the GungnirMB. There was so much to enjoy with this combination that it never occurred to me to move on to my other Schiit amps. I did, at the end of the week, also try the PM-3s with the Valhalla2 and the Vali2. All were excellent combinations. Contrary to the conventional wisdom that low impedance phones should not match well the Valhalla2 or the hi-gain-only Lyr1, both of these amps played well with the PM-3. Extremely well. For Tube Rollers: Tubes rolled for synergy testing with the PM-3 included: '59 Amperex Bugle Boy ECC88 'D' Getter, '64/65 Siemens E88CC, '66 Telefunken E88CC, '66 Amperex PQ 7308, '69 Reflektor 6N23P ODPG, '73 Reflektor 6N23P ODPG, '73 Philips SQ E88CC, '74 Reflektor 6N23P SWGP, '75 Reflektor 6N23P SWGP HG, '77 & '86 Reflektor 6N3P-E (adapter reg'd). All these of these tubes played well with the PM-3s; the typical known characteristics of all these tubes came through without any anomalies. My favorite tube combination? Both the '77 and '86 Reflektor 6N3P-E in either the Lyr1 or the Valhalla2. (Similar sound profile to the best Reflektor 6N23Ps but with a little less energy and diffusion in the upper bass/lower mids.) Beautiful match with both the PM-3 and the PM-1.