Real owners rate these about evenly: 53% of 352 HiFiMan Sundara owners recommend it, vs 58% of 93 for the Sennheiser HD 620S.
Verdicts aggregated from Reddit, enthusiast forums, and YouTube owner comments — affiliate reviews excluded. Sample sizes differ; judge accordingly. How we score
“They won't break. I've got a opair of the 2020 Sundara's and a recently purchased set of Arya Stealth. They're both perfect. Sound wise and build quality too.”— Kevbassman on Reddit
“Absolutely the Sundara gives you way more than its price suggests clean planar bass, great detail and a neutral tuning that honestly captures most of what people love about higher end cans.”— Ornery-Ad-9419 on Reddit
“I think the. Sundara is super overrated. It's fine, nothing special, has some quirks/problems that many better headphones in and above its class don't.”— drwafflefingers on Reddit
“Just got my 620s yesterday, I like it, which is saying a lot for a closed back. I think it’s easily one of the best closed back headphones not only in the price range, just in general.”— MoonWun_ on Reddit
“Crazy enough, the HD800s and the HD620s share the top spot in my endgame headphones. And the price difference is over €1,000. I just can’t believe what the HD620s deliver for €279.”— No-Desk-1808 on Reddit
“I think technically the 620s but the design of the ear cups means they have this bit that protrudes into the ear cups (I think the anchor for the headband) and it’s quite uncomfortable (at least for me).”— gussic on Reddit