It's weird, going from memory (since I now haven't owned either the z1r or trio in a few months), I hear things differently than
@macdonjh in that the trio was always the sharper one of the two to me. I know. A lot of people find the treble on the z1r can run a bit hot, so perhaps the sharpness I heard on the trio was due to the attack from the tia ba drivers vs the dd tweeter treble on the z1r.
Regardless though, I got the z1r first, and just like with the nio, the trio is one I likely wouldn't have even bothered with if the fit was better for me. Both have the same sort of mild v shaped signature that I think it's probably a bit redundant to go for the other if you already have one you like unless there happens to be some specific qualities you are looking for that one might have over the other.
Since you already have and enjoy the z1r and more importantly, it fits well, then as good as the trio is, probably not a lot of reason to add a relatively similarly tuned and similar performing iem to your lineup.
I do miss both my z1r and trio though.