All in one unit for headphones- help me decide

All-  I ordered the Naim atom headphone edition, and should take delivery on Saturday.  So thanks everyone for your advice, comments, and help in my decision.  I’ll follow up with a post in a week or so to let you know my listening experience. 

@meiatflask If you truly want to go a budget route, I'd consider a Poly Mojo2 as your interim step - it's a portable headphone amp and you can get them $500-800 (used/new).  You can connect it to your phone or external streamer (including Chord's poly).  This can then become something you can use for travel or share withe kids or grandkids.  I think you'll appreciate your Sennheiser's on it. 

@soix - point well taken.  I am treading a bit softly here as the last time I really lived with headphones was in college 40+ years ago (had stax electrostats back then).  So perhaps I view this in two steps, with the second more expensive step going the route you suggest after I have lived with a one box set up and confirmed my headphone life is here to stay.  I figure with my just purchased HD800S and the Naim or Auralic, my investment is in the 5-6k range, which is a pretty easy step to make before upgrading to something more serious and delegating the all in one to one of the kids or grandkids.

Your headphones deserve an amp that’ll get the best out of them and highly doubt you’ll find that in an all-in-one unit.  I’d find the right headphone amp and get a separate DAC/streamer to handle the rest.  Is it really worth the sonic compromise just to have one box instead of two?

@v-fi  thanks- I suspected as much.  I will delete them from my consideration list.  And thank you for the re-stating of my requirements.   

Chord Hugo TT2 +/- Chord M-Scaler + streamer such a Zen Streamer.

@freediver Pathos does make really nice stuff but the original post has more criteria for built in streamer and ability to play files from an SSD, either internal or external via USB. I was about to recommend the T+A HA200 as one of the best solutions out there, but it too is missing those features.

I haven't heard it myself but the Matrix Element X2 is supposedly really well rounded, and I think it checks all your boxes for features. 

Pathos "Inpol Remix Mk.II" & "Classic Remix Mk.II" both have headphone circuits specifically designed to be as good as stand alone units costing big $..I can attest to the quality of the Classic Remix Mk.II,using it with HiFiMan HE1000V2,Audeze LCD-V & Focal Clear MG..

@v-fi  +1

Very few integrated components with speaker outputs have quality headphone outputs… even on $10K units. I have heard some people say there are some. But I have never heard one.

So I would definitely nick the two bottom ones. 
 

I haven't heard the first two, but can confirm the Rose and Cambridge models are not what I'd call really serious headphone solutions. They are fine for casual or late night listening on a $200 headphone, and I'm glad they have the option. But for a great headphone like HD800S you really want something more than those. 

I auditioned the Naim - I it was very pleasing and a significant upgrade from my preamp with a headphone jack.

I would consider separate headphone amp and Bluesound node over the a unit with amp section and headphone amp.