I felt the same way the first 2 or 3 times I tried autoEQ profiles (I kept coming back to it because it was so strongly commended, but every time was revulsed that it sounded "wrong" and uninstalled again). What eventually converted me was that I got treble fatigue after a few days of using the HD800S, a headphone that I otherwise absolutely adored. That was only as self-diagnosis, but I'd experienced something similar with the analytic pads on the DT1990, and both of them have spikes at 10khz. So I set it to Harman to get rid of anything "weird", and was initially just grateful that the ear pain didn't come back.

Now I'm used to it, and deviations from Harman are what sound off to me (sometimes Peace resets to a flat EQ, and I'll notice immediately that something is wrong). I don't feel too strongly that it's better sounding, I think it's mostly an issue of the sound you're used to.

I've also grown to like Harman on other headphones, but an exception is the 7hz Timeless. I don't know why it's an exception since I like Harman everywhere else, but I think they go from being exceptional to sounding like ass.