The P channel differential driver stage with the same polarity output stage is what Bascom King described as his amplifier design for PS Audio's BHK amp some 5 years ago. According to King he got his idea after listening to a Yamaha amplifier which had this configuration and wondering why it sounded different and better than the typical Japanese fare of the day. The link below is a YouTube clip where describes in general terms this output stage and the required driver:
He starts around 11 min 30sec in to explain in detail. Nothing new under the sun, rising sun in this case.