Not sure what projector you intend to use with this or what the room conditions are like. ALR long throw screens don't give you huge returns at no cost. It does cost some image quality the second you use a ALR screen as it will introduce sparkling into the image.

Per the specifications page, you also must ensure the projector is no less than 1.4x the screen width away for it to perform properly and not reject light from the projector itself.

https://elitescreens.com/products/cinegrey-4d/

I'm not a huge fan of ALR screens unless they are for UST projectors.

I'd much rather see a white, or normal grey screen in most rooms and then proper light control in the space. But, there is nothing specifically bad about this screen and it should work quite well. I would go for the larger size if you can do so.