I never have reached the holy grail that I read about, which is more depth, wall to wall soundstage and that holographic feel.
I don't think room correction is the right approach to this problem. I use room correction myself, so I am not discouraging you from trying it. Room correction, or simply EQ, can yield huge improvements in bass SQ, but it is not the best approach to issues relating to imaging and soundstaging, IMO.
I strongly suspect that the problem is your listening room.
If you want more depth, I'm afraid you're going to have to get rid of the cabinet between the speakers. IME, any large object between the speakers diminishes soundstage depth and interferes with "holographic" imaging. If you could get your speakers farther from the front wall, that might also help improve depth.
If you want to improve the overall size of the soundstage, you may want to look at the ratio of diffusion to absorption in the room. Is the room overly damped? Adding diffusion can dramatically improve soundstaging.
If you remove the cabinet from between the speakers and add diffusion both behind the speakers and at the first-order reflection points on the side walls, I think you will be well on your way toward finding what you're looking for.