Well, lets not confuse the general character of the EX1000's treble w/ a peak or two that some might be more sensitive to than others.
The cable swap only seemed to remove that annoying peak for me, nothing else. It doesn't make the EX1000 sound like an Orpheus. Still sounds like an EX1000. So yes I prefer the cheaper, crappier cable from the EX600 over the pricier EX1000 cable. I've AB'd them 3x's now so I must have massive expectation bias. I like listening to music w/o discomfort, call me crazy.
Yes, a poor seal on the EX1000 will really thin out the bass and the peaks will rape your ears.