Yes, it does seem as though the music is coming from behind the plane of the speakers. I have noticed that the farther away from the front wall speakers are positioned the more apparent the depth. In my experience that has been true with all speakers, monopoles, dipoles and omnis.
This evening I remeasured the speakers and allowed my Anti-mode X4 to recalculate the room correction. I was pleasantly surprised that there was very little to correct! Anti-mode shows a measurement with the corrected curve superimposed over it. It pulled down a room mode peak at 40dB about -3dB and made an additional three other small changes. When I toggled the corrected curve and the uncorrected curve, in bypass mode, the difference in sound was almost indistinguishable!! I manually brought down a small peak centered at 2kHz that was also present and the resulting frequency response is very flat with a slight, (and desirable) rising slope in the bass and a gradual downward slope above 2kHz.
This afternoon a good friend, who had been the principal trombonist in the LA Philharmonic for over 30 years, came over to listen. We played several recordings including some LA Phil ones that he was playing on. He was quite impressed and very complimentary of the X5's. Interestingly, most musicians I've ever known are unimpressed with audio systems and have some of the crappiest playback equipment out there. That my friend was impressed is really a big deal and says a lot about the X5's!