What are your favorite songs or albums for illustrating a deep soundstage?

Nice setup @blisshifi !

Glad you were able to squeeze a bit more out of it. Speaker and listening chair positioning is critical. Looks like you got room acoustics covered as well. Very cool. 

I recently stumbled across an incredible live Norah Jones album "'Til We Meet Again (Live)". Several tracks stand out as impeccably recorded songs, certainly for musicianship, but especially for absolutely stunning depth, spatial information, and remarkable live presence. If you want to listen for truly wonderful soundstage acoustics, this is for you. HIGHLY recommend tracks 2, 4, and 11.  I am constantly adjusting things in my system... Won't bore you with lots of details, but I'm using a Nelson Pass Pure Class-A amp and Maggie's, and things sound truly stunning. I think I've reached a new plateau. Those tracks are always top of my go to list for critical listening of any new adjustments. You won't be disappointed, seriously. (BTW the album is recorded live in several different venues, and you can definitely hear the differences between the sessions, which is also fun/helpful.)

Tomorrow,Wendy by Concrete Blond on cd.

@blisshifi 

What happens to the image when the tweeter array is on on the inside (switching the left and right positions)? I would expect less toe in would be required and a a much better focus of the image but with the narrowing of the sweet spot.

@danager What you suggest is true for Magnepans, which I confirmed when I had them on the floor last year, but I believe these speakers may have different results to the design of the line array midrange drivers inherently having a very narrow dispersion pattern. T+A has recommended not to have the tweeters on the inside. My assumption is that there may be too strong of a treble response and the mids may not properly hit the ears due to the narrow dispersion. I would anticipate the crossover points would also be different, but I haven’t compared. Perhaps when I have some time I will experiment and see!