Can headphones ever be as good as high end stereo?

I have older Stax and newer Sennheiser, Audio Technica and Klipsch phones/buds. Each is different and has its charms. If you like the sound of Electrostat speakers or Maagnepan, you will like the Stax and/or other newer ES or planar magnetic headphone options out there as well. Sennheiser tends towards a warmer less bright non-fatiguing kind of sound overall. Klipsch and Audio Technica are both good as well but sound more like most other good phones.

In some ways....better

When choosing phones, don't forget to give how and where you will use them and overall comfort ample consideration in addition to the sound. Like shoes, different styles/designs may be more confortable to wear and work best case by case for different people. That's one big reason among others that there are so many different kinds/styles of phones out there today.

Neither losing nor gaining, just different.

I went through that phase years ago too. The wife complained about the volume levels that I listened at, she prefers quiet, background music levels, so that she can talk with me. So I went the headphone route, she didn't like that either, because she still couldn't talk with me. I suggested a seperate listening room, she didn't like that idea either. LOL! So I asked her which she found to be the least objectionable, and it turned out to be the old way, stereo in the living room.

We have kind of comprimised on the volume levels. I still turn it up a bit more when she's not around, but it is louder than she wants when she is around. As I've told her, we can't all be happy at once, so we take turns. Her choices of TV programs is terrible too, but she has her times holding the remote. I just find other things to do.
That's life being married, it's all about comprimises.

If you haven't already seen it, I think you'll find this review by Chris Martens in "The Absolute Sound" to be informative and helpful.

My Stax experience is limited to an older model, but based on that experience, and consistent with the author's comments, I suspect that the most notable upsides to the current higher end Stax models relative to most speaker-based systems are likely to be cleaner, faster, more accurate transient response, and increased detail and resolution. And putting aside the obvious differences in imaging and soundstaging, I suspect that the most notable downside (depending on your present system) may be some reduction in the "weightiness" of the bass.

And of course there will undoubtedly be differences in tonality relative to your present system, which you may or may not prefer. As others have noted, subjective reaction to any headphone model will tend to vary widely among different listeners, so an audition is essential.

Personally, I find having electrostatic headphones and dynamic speakers to be nicely complementary, and I wouldn't want to be without either.

Regards,
-- Al