Upgrade to atmos 7.1.2 vs 7.1.4 vs stay at 7.1

You are correct in that the duct work is the yellow painted area. I have 40 inches in front of MLP to the duct work and 36" to the back wall. Room is about 19 feet deep and 11.5 feet wide. I thought Atmos was encoded on some of the regular blurays as well, but I think as more 4k content comes out, they are going to push that format and include atmos mix on those discs and not on blu ray from what I hear. This site has been a money pit for me. LOL started with some rti10s and a csi3 centre and some r15 for surround and a velodyne sub..and have progressed to the current setup. Now if only the kids would go to sleep on time so the wife and I could enjoy some non-cartoon flicks...well, at least we all watch the marvel movies. Of topic, but the SVS aseq1 definitely helped tighten up the bass on my dual subs.
No worries about jigging something up to support the speakers, I can do that, ideally don't want to cut into the beam of the drop down ceiling to place speakers, but will cross that hurdle once I get there.

It's funny you mentioned the svs speakers. I was looking at those as well but then was thiinking it probably better to stay in polk lineup. But I could mount the svs under the soffit as well for optimal spacing.

I have been debating whether to just remove the back speakers and use a 5.1 setup instead. I remember reading that monopole is the best for the rears, but was getting a decent price on the LSiFx here. They have a pretty crisp sound to them. I would need some speakers that aren't too deep for the surround backs. I don't really want to do in wall rear speakers either. In all honesty, I have been thinking if a 5.1.4 might be a better setup than a 7.1.2 for my room. I have no problem jigging up something to keep the in ceilings in place. The tiles are soft, so was expecting to have to make something to keep them up there. Do in-ceilings need a hard surface towards the front for proper sound production? Not sure how much of a box they need around them for optimal sound. I am not the best carpenter, but can get the job done, especially since the work won't really be visible.

MLP(main listening position...aka where I sit and enjoy a beverage while watching a movie). You can't really see it in the photo as it has a bunch of cushions on it in the pic so you don't see the sofa.

As far as subwoofers are concerned, there are a couple of 150 pound SVS beasts lurking behind the sofa...taking up much of the room behind there are a pair of PB13 Ultra's...no plans to upgrade those beasts anytime soon. Putting them back there really helped clean up the room at the front which was getting super cluttered when the subs were there. Once I ran the AS EQ1 calibration, you can't really notice that they are right behind you. Using a Pioneer SC 1227k for the AVR. A B&K 5 channel power amp powers the front 3 and the side surrounds. Also using an Emotiva xsp-1 preamp hooked to the subs and the power amps and avr to emotive in home theatre bypass. The preamp is for 2 channel music (which I rarely get to sit and listen to these days). If I go atmos, thinking of a midrange Marantz AVR potentially to replace the preamp, avr and aseq1. But finding an AVR will be a separate journey!
Thanks for all the discussion/suggestions so far.
Oh yeah, the rear tweeters are currently at....let me go measure...70 inches from the floor and about 19 inches to ceiling.

That's food for thought. I shall investigate those settings on my current AVR, it's something I hadn't thought of. hmmm...maybe I should look for a good deal on some LSi7's for my rears! I spend more time thinking about the HT setup than actually using it! Currently making some panels for the rear wall that will double up as a bit of shelving on the back wall. Almost finished that, then gonna make one 6 inch panel that can go behind the centre channel during movies...Hmmm, I could store it on the new shelf in the back lol. Then gonna use some black speaker cloth to darken up the ceiling in front of the projector screen that can be rolled out during movies and then back up again when not in use (yay, multipurpose rooms!). Don't want to paint the current tiles and the speaker cloth allows the vent duct in ceiling to breathe.

Well, I ended up installing 4 MC80's as they didn't have enough of the MC60s in stock. The MC60s would have been easier to install as they aren't as wide, I had barely any room to spare in between the joists with the MC80s. I figured they are cheap enough to get 4 of them and not look back, even if it is only an incremental difference between 2 overhead speakers and 4 overhead speakers in my setup. It is amazing how much stuff is in the basement ceiling when you finally get around to installing things and how you can't position things as nicely as you would like. I finally got around to downloading the atmos demos from the dolby site last week. I had initially lowered my surrounds about 6 inches from my initial 7.1 setup so that the bottoms of the LSIfx was just above my head. The position of the audio from the surrounds in some of the atomos demos seemed a bit too high up. I then lowered them another 8 inches or so, they are just about head level now (tweeter is still above head level). The atmos demos sound better, the sound is more cohesive (I didn't change any calibrations or settings in the AVR). Interestingly, when I was watching the blu ray of the original Jurassic Park, the sound from the sides sounded like the speakers were too low on the wall and the ambient sounds too directional. Go figure! I didn't get a chance to move the surrounds back up to see how they sounded with Jurassic Park. I figure there is no one surround speaker height that rules them all.

I remember hearing CEDIA was recommending to place a bit higher than Dolby's recommendations but I never saw what their actual recommendations were. I must say it does sound nice. During the rainstorm scenes it feels like a cool little breeze is blowing in the room, even though there isn't really one and the PB13's aren't making things move either at the time, just all in my head. Weird how that happens sometimes.

It keeps on snowing this winter!