Sounds promising.
I know I wont notice a huge difference in quality from my ZA Basso but I do hope its faster.
People with these and the RHA 750s say EPH100s are faster.
The Yamaha's come from the same lineage as the famous NS-10M Studio Monitor, the NS-1000M Monitor and the Class A MX-1 dual mono power amplifier.
Yamaha is a music company first. This has always been evident in the quality of the sound signatures in their consumer and professional products. They were one of the first Japanese companies to produce power amps and receivers that actually sounded good, which was rare for Japan for a long time. How things have changed.
Not having heard the ZAs I cannot speak comparatively; however, what I can say is that the EPHs are very musical, transient and listenable. The sound is organic and engaging. Bass extension in the sub-bass region is quite present and detailed. That's the one thing about Yamaha products that remains consistent. They are detailed.
Daft Punk's Doin It Right is IMHO flawless represented. ABing them with the ATH-IM70s reveals a significant loss do detail in the upper mids and highs. Decay is choked off and the soundstage is both narrowed and displaced. The EPHs make the experience of listening to the same material abundant key more intimate due to one's ability to hear more of what's on the track and not just some engineer's idea of how his hardware should present so done else's art.
You be the judge.
could have got them this week if I paid 40 more. 
