This LG is not an ultra-high contrast projector. That seems to be the biggest difference between the two LG models. The CF181D was "marginal" in terms of black levels - one of those that most of the time makes it as an ultra high contrast projector, but other times/content, might seem a touch short of those "better blacks".
The LG AF115 home projector, even with its dynamic iris on, is not an ultra high contrast projector. Overall, its black level performance should be most similar to the Epson Home Cinema 8100 which is a lot less money, and to a lesser degree, the blacks of the Mitsubishi HC3800, which is a DLP with great blacks for the under $1500 price (no dynamic iris).
Black level performance should be acceptable in the family room type environment - without full lighting controls, dark walls, etc., but even for a $2K price, the black performance will be the AF115's weakness.
First pair, the AF115, slightly overexposed (intended more, sorry), and normal. Directly below those two are the CF181D similar images. Those four are followed by an assortment of other projectors including JVC, and Panasonic.