Lack of depth problem

Given the full range of the speakers, you might want to try bass traps in the corners behind the speakers. If you use ASC, point the seam kitty corner (45 degree angle). If you stack them, do NOT point the second trap in quite as far: you will kill the sense of ambience even as you tighten the bass.
First reflection points, but also floor (I have 2 half rounds on the floor in front of the speakers, reflective side TOWARDS the speakers). Also, try the "clap" test in your room. Simply walk from one end to the other and see if you have slap echo. If you do, damp it. You can put up anything, but preferably something with folds in it (this is per Alton Everst, in the Master Handbook of Acoustics: Mr. Everest posits that sound is damped better in folds than something without folds). I don't know if you can do this in your room.
I recently put a half round on the ceiling and found the effect rather...effective. I had 2" fiberglass on the ceiling (it's still there), but the shape of the half round scatters reflections considerably better. It also increases height and the sensation of the harmonics drifting upwards.
I also have Real Traps, but find the tuning of the Tube Traps easier, as you can turn a trap to absorb some bass and reflect at the same time.
The room you have sounds great, dimension-wise, but unless you've done something to it that you haven't mentioned, you'd be surprised how too much upper-bass can murk up the sense of depth. What room treatment DO you have??

I don't think you need tube traps on the ceiling, Vett. I just like to experiment, having had tube traps since 1988 and still find them great for absorbing bass.
If you have any "jogs" in the room, bass does tend to pile up there. That jog in my room from 13' to 12'8" was piling up quite a bit, something I didn't realize for many, many months. Otherwise, just a couple in whichever corners you can put them in should smooth out any humps in the bass. It's also helpful (but only it it's not overly expensive) to have a height of 6' on the traps, which means 2 of them. I have found that the closer to the ceiling you get, the more the sound improves. I put a box in between my bottom and top trap just to see if it improved,and it seems that higher up is better! You can always try the Real Traps, but it sounds as though you have enough damping for higher frequencies, which are, as I recall, pretty short. I think a 1khz wave is 1" long -- or shorter, so I wouldn't worry about that too much. One could have a tall ficus tree to break up those wavelengths. It's the upper bass that I find haunts most rooms of normal size.