I’m not sure if Carada contacts everyone but they also contacted me to ask what projector I was using and under what conditions after I placed my order. I think it may be a common practice for them to do that and I found there advice was accurate. I bought a 134” 1.78:1 Brilliant White as I have an light controlled room. I’m using the AE4000 from 19’ back and have a perfectly bright picture using eco-mode. In normal or dynamic mode it still projects a great image with all four room lights on as long as the light isn’t shining directly at the screen.
I agree with Potatohead that you should get the projector as far back as you can. I also suggest you get the largest screen you think you will want keeping in mind what Randy said about fast moving scenes sometimes being to much. I’m sitting 14-15’ away from my 134” screen and fast motion is just at the limit of what I want however anyone prone to motion sickness would likely puke if they watched it for to long. Just last night I put on LOTR FOTR and during the scene in the Mines of Moria where Boromir almost falls off the stairs I got an adrenalin rush from the vertigo it cause. Just remember you can always cast a smaller image than your screen size as long as you’re willing to deal with the black bars which you can make DIY masking for pretty easily.