Ok, so the Fiio D3 seems to have this really bad grain on certain songs that isn't there on the E17. I guess I didn't test them enough, and the soundbar didn't pick up such distortions.
When the Fiio D3 is behaving (the vast majority of the time), it sounds very close to the E17, being just SLIGHTLY warmer, and bassier than the E17's DAC (which is more neutral). All three DT990s sound bassy off it. I can definitely tell the E17 is a better DAC, even when the Fiio D3 is behaving.
I also tested the Fiio E17 undocked with the Fiio L7 line out dock. Sounded the same as when it's docked, which is a good thing, in case I return the E09K for something else, though I like the synergy between the E17 and E09K, and love that I don't have to touch the E17. I turn off the E09K, and the E17 turns off. I turn it on, and the same result. If I got another amp (thinking of getting the Asgard, for the .5 output impedance, and more power than the E09K), I'd have to deal with more cables/clutter. I like the E17/E09K's simplicity. We'll see.
I am almost certain that I'm keeping the 250ohm regardless. On my favorite chillstep tracks, the sub bass is actually more audible compared to the 32 and 600ohm (and the bass tickles my ears, where it doesn't do that on the 32/600). I'm still quite surprised at how fantastic the 32ohm is, and how close in SQ it is to the 600ohm. If it wasn't for my need for more bass, the other two are superior in balance. The 250ohm sounds more refined than the 32ohm, but the 32ohm sounds 'better' because it's less v shaped. The 600ohm is both refined and better sounding than the 250oh, if bass isn't the number 1 factor, and the one I'd go with every other time.
Now for some brief gaming. RE6 demo, gogogo.
Before I play, I must say I agree with Tyll at Innerfidelity about the 32ohm. They are meant to be driven by portable sources, but portable sources tend to SUCK. This makes the 32ohm Beyers kind of useless in that the purpose to get them was to use them on not GREAT equipment, and to make them sound as good as they truly are, you need to amp them as much as you would the 250ohm. It doesn't make sense really. This is why unless you absolutely need a part time unamped headphone (which isn't gonna sound anywhere near it's best without a proper setup), it's just better to get the 250ohm version ANYWAYS. They both need amping, the 250ohm sounds cleaner when amped, and it's safe from amps that have high output impedances.
NOW, if you happen to be too late and already own the 32ohm, worry not, they are amazing headphones. Just, you're gonna need to invest some money in them like the other two to make them sound almost nearly as good as the other two, and you do get that possiblity to use them unamped, as they can get loud enough, while the others may not.
Man, there is a clarity in the 600ohm that isn't just quite there on the 250ohm, and I may be willing to sacrifices those few points of bass for that 600ohm refinement. AGH. We'll see.