These are a killer deal at 39 USD. You're essentially getting the Porta Pro with a mic and thicker cable, which is normally 50 USD. In terms of sound quality for the price this thing was probably totally dominant until the Chinese Hifi market exploded with things like the Tin T2, Moondrop Aria, Dunu Titan S and Truthears Hexa. That said, these compete fairly with the Tin T2 and they have an incredible warranty. Additionally, they weigh very little, they fold and their pads/driver slips are cheap as dirt. I really like the aesthetic, but that's a pretty personal thing.
As for subjective sound quality, I think they're fairly well tuned. I won't say too much about frequency response, but I think they punch above their price point in terms of overall resolution and clarity. I will say that they don't seem as clear vocally as the Tin T2 IEM, but they do better at different things. The Porta Pro just seems pretty relaxed in the upper regions, have okay mid range and seem like they have a lot of mid bass.