My Hifiman sundaras are my favorite over ears for sure, my Hifiman RE2000 iems are my favorite iems (or “headphones” in general for that matter) I’ve ever owned though. They’re good with any genre of music and the tuning is perfect for my ears. They’re very warm yet still analytical and detailed.

Depends what headphones you’re trying to drive. Planars for example benefit greatly from an amp.

How did you eventually figure it out?

For me it was because I was trying to find my preferred sound signature, and chifi makes it much easier and less expensive 😂 For iems at least I found my end game in Hifiman RE2000 I got on sale. I also have Sundaras and focal elegia, open back vs closed back for obvious reasons.