PM1 Owner and user
I really like the OPPO PM-1. I am able to use it connected directly to my OPPO-105 Blue Ray Player headphone out, My AV Receiver Headphone out and for music only connected to my Lyr headphone amp (which is connected to my Musical Fidelity M1 DAC). The 105 and AV Receiver's headphone amps are more than adequate to drive the PM-1's.
When I am listening to music only, the DAC is connected to my 3TB External Drive (it has 15K+ tracks of 192K/24bit music), which is attached to my Computer. I use JRiver to control play. The sound is fantastic. I stay away from subjective terms like warm, dynamic, etc. What may sound great to me using those terms may sound completely different to someone else.
I love the packaging and it one reason why I wouldn't have waited for a PM2. Having had several OPPO products, the packaging and quality of the product just increases my enjoyment of the experience with OPPO.