I don't want to unduly get your hopes up but I think you won't be disappointed
Like yours my first Zenith were probably already in phase as, once the tip situation was sorted out, I didn't identify any of the typical issues reported on out-of-phase units. That being said, I only ever listened to them to try and make sure they worked properly. It verged on greatness but something was amiss. I received the replacement earpieces yesterday, listened to the first-batch Zenith for ten minutes before plugging in the replacement Zenith, and, well - let's just say I didn't feel like going back to the first-batch ones. In fact, after a handful of tracks I started venturing out of my Audio playlist and towards songs I just love to listen to, so sure was I that things were working correctly, and so great and immediate was my aural satisfaction!
They do hit harder than the R1 I find, not in physical impact, but through a more aggressively detailed tuning, with more of an emphasis on mids, especially upper-mids. This with the black filters. I'm not feeling fatigue though, it's quite expertly done. Opening the ports also makes a bigger difference this time around. Not quite open-back-like, but very close. All in all these sound very much in line with what Bob advertised: more precision, tamed bass, and an even bigger sound stage.