I recently bought a used pair of Daybreaks and while I felt they were tuned well and sounded very natural to my ears, I was shocked how close they were to the 7Hz Zero:2. Even if they measure relatively similar, I was expecting more of a difference. You can hear both pairs were tuned by someone who likes a neutral tuning with a healthy boost in the bass. So do I!
Don't get me wrong, the Daybreaks still sounded better to my ears. The treble profile works super well. They sound more open, but there's no stray frequencies poking out with certain instruments or any sibilance, which sometimes happens with the Zero:2. But a simple EQ match via AutoEQ made both pairs sound even more similar. I started fiddling and ended up with an EQ curve somewhere between the Daybreak curve and a tilted JM-1 curve (not much difference between those two targets!), with a few concessions in the treble for my own ears. Maybe half an hour of work.
If you don't have EQ capabilities, the Daybreaks are great, but a little EQ makes the Zero:2 sound better to me (!) than the Daybreaks. Ergonomics are about equal, I would say, so there was no reason for me to keep the Daybreaks. People throw the term "giant killer" around willy nilly, but it 100 % applies to the Zero:2. Add something like a CB1200AU dongle and you're golden.