So I’m gonna make an assessment, or really a comparison of the Porta Pro and another popular headphone that I’ve never listened to. 
But from what I’ve been told by people (talking about many of you) who’s opinions I trust and highly respect, I know I’ll love.
I think the Porta Pro could be a ‘baby’ Aeolus.
They use similar synthetic materials for their drivers, and they’re both are often referred to as fun, or pleasant sounding headphones.
Many argue that the Aeolus is a good starting point in the ZMF line because of their warm signature, and their ability to play without fatigue. You get some highs, but not in a microscopic fashion like an Verité.
The same is often said about the Porta Pros; warm, fun, slightly v-shaped, highs are there but non fatiguing. And I always say you gotta start with a Porta Pro!
I don’t know, but I know you guys will chime in and let me know what you think. 
Yaxi Gang 4-Life!