That's a hard question - I like both to be honest. Since I am one of the people that apparently got a Hybrid with working BA I find the Hybrid maybe a bit less warm than the Piston 3.
I took them both out just now to compare them. For modern music I like both - the Piston 3 might be less analytical but the music is easier to listen to - so a plus there. As for classical music I just listened to the beginning of the Passacaglia & Fugue by Bach (Respighi orchestral version) that has some very low brass instruments at the start and that is something where the Piston 3 struggles slightly in comparison to the Hybrid it seems - it lacks some of the "brassiness/overtones". (If you want to listen to the piece, here's a YouTube version:
https://www.youtube.com/watch?v=ChqQFyGmit4 - the beginning is a basshead's orchestral dream I guess
).
Last but not least there's the fit: I feel the Piston 3 Dazzle much less than the Hybrids when I wear them for some time. Might be the lower weight, since the Dazzle version has a plastic housing, might be some other factor, I don't know.
So in conclusion I'd say the Piston 3s are less analytical but easier to listen to and for a third of the money definitely a very viable option. It won't be miles better than the Hybrid - both are very good headphones at their price point. But that's of course just my opinion and might not be what others experience.