Assuming you're talking about the Orpheus 2 with the built in DAC? At least from my experience, it's been consistent that DACs/Amps that are included with premium offerings are pretty underwhelming, and/or you're paying too much of a premium for just on par performance. It's a big reason I wanted the SGL Sr. and original Orpheus without the matching amps.
I know for resale value, many prefer a whole "system", but it doesn't ever seem worth it for me.
That said, HE90 alone, is pretty phenomenal. I would say it's two weaknesses are 1) price lol... it's just really priced extremely high. But I think a reason for that, beyond rarity, is that they really are well built and their quality is easily maintained if you take care of them. Mine are pristine for how old they are, barring just one small issue I have with them. But most pairs I've seen look to be in amazing quality for the years they have on them; and 2) They don't have an extreme wow factor. They are incredibly balanced across the entire spectrum of sound, with just enough technical prowess to be a top performer. But their resolution, spaciousness, etc. aren't going to wow you against the competition. They probably have the best tonality of any headphone, but I don't think it stands out as a real wow factor.
It's one of those rare headphones that you can just put on and just entirely forget about anything else and listen forever. Still very competitive today for sure imo.