I kept mine (same like the one you have) after trying 2 Muses E1 (which were sent to me to replace the one I had without the gain jumper) I noticed a change in clarity and details in Music.
the one I had, was more musical and enjoyable to listen to, it was almost .
The other 2 replacements sounded less accurate and missing the prat I was getting, so I ended keeping it, FYI.
Just enjoy listing...
Did your non-jumper version of muses have more break in time when you compared it to the other muses versions? I got my muses edition in last week and the sound is now substantially smoother and not so bright than when I got it.