Hey
@Hifiearspeakers, just out of curioisity, are you driving the D8000 with a Chord Hugo, Mojo or the headphone out of a DAC?
I have an Oppo PM-3, which is even easier to drive (32 ohms & 102db) than the Final D8000 (60 ohms & 98db).
I've heard them through the Chord Mojo, Hugo, and also the headphone out of a Prism Lyra 1 and Audient ID22 audio interfaces (the Chords at a Hifi store, I own the Lyra and owned the ID22).
Even if any of those headphone outs has more power than what the PM-3 needs according to specs, I've always found them bland and unispiring out of the Chord gear, and also with the Audient and Lyra integrated headphone amps.
The thing changed radically when I bought a second hand AMB M3 headphone amplifier, those usually go for about 200$ used. It just grabbed that Oppo and made it a man.
What I'm trying to say is, planars ADORE stable current delivery more than the watts themselves, the AMB M3 is made for that purpose, and also some Kevin Gilmore amps.
If that happened with a miserable Oppo PM-3, which needs less power than the D8000, and I'm sure is nowhere near special or transparent sonically, this should transform the D8000.
It's worth a try because a second hand AMB M3 costs around 200$ and retains it's value pretty well, you can sell it after without almost no money loss. If the AMB M3 can't make the D8000 sing for you (and, believe me, it should kick it's @ss),
then you'll be sure that you didn't like the D8000 (no remorse after selling, "should I have tried XYZ before selling this thing?").
Give it a try, I think that it should be the solution to the problem.