For all of you who are concerned about the reverberation of Isone (or how Redline Monitor is different), you kind of have to just see it this way:
-If you want to keep the sound as close to how headphone's frequency response is supposed to sound like, being only centimeters away from your eardrums, but want crossfeed so you don't suffer from the drastic stereo panning inherent to headphones, then Redline Monitor is what you want (or any other simple crossfeed out there).
-If you want your headphones to actually sound like speakers placed in front of you, at a distance, inside a room, then Isone is what you want. BUT, you have to keep in mind that if your headphones became speakers placed in a room in front of you at a distance, then it will no longer sound exactly like how headphones sound when they are only centimeters away from your eardrums on either side of your head. To expect otherwise would be completely missing the whole point of using Isone. With Isone, your headphone is SUPPOSED to sound different--that's why you'd use Isone in the first place--to make them sound like speakers in a room, not headphones on your head.
So if you don't know what your goals are or have incorrect expectations, you're going to dislike Isone, because you are not using it for the right reasons. If you don't like Isone, just use Redline Monitor or other simple crossfeeds. But don't continue to expect Isone to sound like headphones on your head. It is supposed to like speakers put at a distance in front of you, inside a room--which WILL change the frequency response of your headphone as the sound interaction with the complex math of HRTF, which takes into consideration how your head and ear shape/sizes alter the frequency response of sounds, as well as how the sound interacts with the acoustics of the virtual room.
I'm not sure why that is so hard to understand. If you take a pair of speakers and put them right next to your ears, at the same distance as how close headphones are to your ears, it's going to sound different from when the speakers are placed at a distance in front of you, while the sound is shaped by the acoustics of the room. You wouldn't expect the speakers to sound exactly the same in the two different placements, would you? Then why would you expect your headphones to sound exactly the same when Isone puts it in a virtual room and placed at a distance in front of you?