I used the ME for two years as the main DAC in my tube amp stereo. I replaced it with the the ME2. 90% of my listening was acoustic Jazz and Classical via Tidal. There is a noticable improvement in sound stage and seperation on my Mission tower speakers. As a photographer, my analogy would be that the sound images of the instruments seemed to be "sharpened", such that their location was pinpointed more accuratly. Listening to Yo-yo Ma's Inspired By Bach his antique cello sounded especially clear. There was a slight improvement in the bass as well, such as on Charlie Haden's Heartplay
I only listened to the headphone amp for a short time. It sounded fine, but I can't really give an informed opinion.
Yeah I use both line out and headphone amp.
I think this might possibly be the information people like me want to read.
ME1 compared to Mojo
A bit thicker and weightier sounding.
Slightly richer sounding.
Fractionally more fun sounding. E.g a buzzy sound is warmer and more buzzy.
Smoother softer sound.
Mojo compared to ME1.
Extra definition puts some stuff right. Instruments have a slightly clearer defined space. Instruments have more definition, e.g a tom-tom beat; you can hear more of the impact of the hand. You can hear more of the defintion of what it going on with the skin of the tom-tom when struck. You hear a clearer decay of the instrument. (Whereas the ME1 some decays can sound dull with having less detail.)
Sligthly less weighty sounding, but might be down to more focus.
Slightly more balanced soundfield.
More crisp reponse to steel strung acoustic guitar, though the ME1 does a really good job.
Cymbals are more focused and clearly defined.
These descriptions are what I mean by the Mojo 'sounding more planted'. More noticable with my (good) desktop active speakers. It feels more sat in front of me. The ME1 by comparison sounds like it's hovering a little, and as if I am listening to speakers from off centre. Additionally being slightly less focused. This is by no means a criticism of the ME1 though, because for the £150 I paid it's very good.
Bass notes sound drier, tighter, and more defined. The ME is a touch boomier.
Copes with congested music better making it sound pleasant, whereas the ME can make congested music less fun to hear. In other words the Mojo makes music better.
Smooth because it's clearer.
Bit less sibilant.
Bit more transparent.
Bear in mind my audio kit is not top-notch so others will hear more.
It does sound like the ME2 is doing some of what the Mojo is doing but keeping the Meridian sound. A bit of extra clarity focusing and revelealing better textures.