I use an anamorphic lense and I'm at the shorter throw range, so I have a 2.41 image (i.e. slightly skewed).
In my opinion, go large 2.4. This sounds terrible, but with 1.78 I still keep my lense in place - because it fills the screen (by zooming) and crops a little bit off the top and bottom. That's how much I don't care about 1.78 anymore!
Once you see epic movies in larger than life, you won't want to go back...
You want to talk about researching it took me 2 years to buy my projector, and now 5 years to build it's room (researching how to do it). My carpenter that's helped me do some things thinks I'm crazy and wants to know what it's all about.
I told him recently he will be disappointed because once my room is finished it's not like I'm actually going to use it, I just like building it out.