Does the first reflection point actually matter??

Another observation is that low bass is radiating omnidirectional so those low frequencies are radiated behind the speakers. I see great corner bass absorbers. But there is also thin foam that will not help against that the bass is reflecting from those surfaces. Instead those foam will only take hi frequency reflections and also contribute towards "over-damped" feeling. Maybe remove or replace with thicker absorbers. 

I found some mid/high absorption behind the speakers to be beneficial, the corrugated foam is there for that. As you say, it won't provide any absorption at low frequencies. It's a balancing act though, too much absorption definitely kills the sound. I've tried diffusers in place of the absorbers in that position, but I prefer the mix of both.

When my house was built I had some input into the room dimensions, which follow one of Sepmeyers ratios to avoid stacking of bass modes. This seems to have alleviated the need for heavy bass trapping, I certainly don't have any obvious bass drone or boom.
It probably also helps that my ATC speakers are blessedly free of bass bloat. Though quite extended, the active SCM100 maintains iron fist control of the bass for a taut linear sound. 

Is those cool white 3d diffusers the "styrofoam" or other material? 

They are Vicoustic DC2 styrofoam diffusers. Lightweight and easy to hang with removable 3M velcro tabs.  
The diffusers can be applied more liberally than absorbers before detrimental effects on balance - but everything has its limit, so best to add any treatment in steps rather than slathering it everywhere.

This has been an interesting thread. I’ve got a buddy who has gone completely opposite.

14x15’ room with 10’ ceilings, hardwood on concrete, drywall... listening sofa backed up to the rear wall... subs in both front corners... speakers pulled out 6’ from the front wall and positions to take advantage of reflections to create a sound presentation that can best be described as total immersion.

Ok, maybe imaging is not the best and some songs can be a little bright but overall the sound is very lifelike and enjoyable.

Yes, reflections can 'enhance' the sound - though unchecked they will play havoc with precise imaging/scaling and the individuality of recordings.
Some can't get enough of reflections - Amar Bose built a company on speakers leveraging enveloping reflected sound. Not for everyone though. 

I've certainly enjoyed previous systems in rooms without any acoustic treatment, though wouldn't go back to that now.

There is so many variables. 
We have all different speakers with more or less amount of high frequency output.
Some sit with a "full range" tang band 8" and others has more/higher frequencies + added super tweeters. 
I guess the last example will probably more likely need more absorption coverage area of the walls.
(Then it is a good idea to take in and out the carpet if switching between those two different speakers in the room. A way of "Tuning" the room depending on what gear is used.)

OK, we can see it as the acoustics in the listening ROOM and the acoustics in the recording ROOM. 
The record "CHASING THE DRAGON - AUDIOPHILE RECORDINGS VOL 1" from Mike Valentine. Has two tracks:

2. Cello Interior: Bach's Cello Suite No. 1
Interior: In an English church, 3 M50's were set up to record cellist Justin Pearson performing Bach's Prelude. Between the mic, a Jecklin Disc was placed. This increased the separation of the spaced pair. The acoustics of the church are wonderful!
3. Cello Exterior: Bach's Cello Suite No. 1
The same microphones, performer, cello and the same piece of music... but this time recorded outside in the graveyard! How important are acoustics? What would it sound like to be able to remove the church from the last recording? Compare the tracks to hear for yourself the results of this interesting experiment! Which do you prefer?

It is very benefiting that our room do not has its own colorfull acoustics then you are not hearing what Mike Valentine intended us to hear in his recordings.
If we exaggerate and take and rig our stereo in the "big English church" as our listening room and listen to track "3. Cello Exterior".

Then we will hear almost the same as if we used well treated room/earphones and listening to track "2. Cello Interior"!

So if we are listening in a reverberant, colorful room. We will get used to that and at the end it will be our preferences. But everything we play will get that reverb and color. That were not intended to be there by the technician/artist. But you now prefer it but we can if we want always adjust our preferences. (See below) :)

As in those two tracks, examples above I actually in the beginning preferred track "2. Cello Interior" over the "3. Cello Exterior". 
Because that is the normal sound that we are USED to hear it in a reverberant space as a room is.

But after a while I noticed that I changed opinion and started to like "3. Cello Exterior" more and more. When I discovered that when the room were removed and all of its reverberation and color THEN I easily could hear how the cello itself sounded and how the whole resonant cello body sounded without any room smearing all over it. That were a great educational experience for me (not every day you hear a cello playing in free air outside (closest we get to a anacoic chamber))

If I ask someone with Floyd Toole level knowledge of loudspeaker-in-room acoustics (which I can with Billy Woodman at ATC),  he would tell me that consistent spectral content of direct vs reflections is the key to imaging.  If the reflections look very similar in spectral content to the direct sound it will image well.  That's why he builds wide dispersion loudspeakers. Narrow dispersion loudspeakers, having different spectral content off axis than on axis, sends spectral energy that does NOT sound like the direct sound on reflection "zones" (love this word Duke, well done).  Its all about the sum of these two complex sources of (direct vs reflected) energy at your ears, because when they combine with each other they partially cancel or completely cancel each other.   Longer path = longer time= phase shift.   This is the idea of nearfeild monitoring in studios, reduce the amount of reflected energy by sitting closer and moving the speakers further from the walls (smaller triangle).   Now you can hear more of your monitor and less of the room.  Engineers use this idea to help them get a more consistent sound in the different rooms they work in without changing speakers, using EQ or DSP (all of which adds another "veil" to the direct sound).  I remember seeing Kevin Shirley mixing about 2 feet from his speakers which were about 2 feet apart.   Not so much "room sound" in such a set up.

Brad