I know what you mean about Nick's theater. Very awesome. I especially like the custom fabric on his acoustic panels. That really adds something to the room IMO instead of just being the typical black rectangles you see in other builds.
The AT screen hasn't affected any of my choices but the room itself affected my decision of going with an AT screen and the in-wall M22's. The entrance to my room is right at the front left corner so I didn't have the option of building a false wall like Nick and others have done. And I couldn't put the screen on the opposite wall without some semi major construction because there is a storage room in the back that also houses the big water distribution box that all the pex lines connect to and my water heater is in there too. That narrowed my choices down to either doing in-walls and an AT screen or doing towers that I would have to side step past to get into the room. I was OK with the 2nd option but my wife wasn't. So in-walls and AT screen it was. The sub box is actually in your line of sight when you come into the room. That's how close the entrance is to that front wall.
For the screen itself, that will be DIY as well. For about $75 I can build a frame out of 1x4's and wrap it in matte white milliskin spandex. I already have the material, just waiting until the rest of room is done before building it as I don't want to get the dust/dirt on it from the other projects. Making due with a bed sheet for now. Lol. I've read that the spandex will work just as good as factory screen material so I figured it was worth a shot to save some cash. If I don't like it and decide to go with a Seymour or something I'm only out $75 and I'll know for next time.
UMC-200, XPA-3, XPA-5, iNuke 3000DSP, M22's for LCR, 4 QS8's, 2 Ultimax 15" in DIY 12cuft ported box