jon parker
Headphoneus Supremus
Welcome to what you thought was a hobby but is now a lifestyle.
You can never have too many IMR's so yes buy more.
I do not have either EDP ACE or Zenith ii but from previous experience and all the views expressed in this thread your ACE will only get better with around 300 hours so you still have more to come from them. I do own the OG Zenith and the porting system did not make a huge difference but that is a different DD set in there, rather than giving a larger stage it gave more space in the space available, the new Zenith may be different though.
The Zenith II's already have a massive space. Listening to some Bach the other night...never heard classical music so alive, vibrant and intoxicating. The space of the instruments and accuracy of tonality is very much like hearing it live. Freakishly so!
It seems like in Open port mode you cant improve that much on the already huge stage but I could hear the bass and mids tightening up in closed mode, becoming more focused and punchy. Wont know until fully burnt in but its looking like in open back its more airy and loose...as our IMR Queen, Her Majesty NellieG has alluded to above