Product review (5 stars): So now the Crystala unit is installed and working fine. After flushing
Purchased at $9.99 during their promo offer. Originally thought it didn't fit because it wouldn't turn and cam in, but when I purchased a "real" LG filter (at $49.99), all the features looked to be the identical (checked length and position of O-rings and lugs with digital calipers, and compared side-by-side with the LG unit and the "HD" HDX unit that I just removed), it was identical to the LG filter. The LG filter also resisted turning and camming in as well. Turns out I had to push in REAL hard to get the front end inserted far enough for the lugs to engage and allow rotation to cam in - seemed to be the same issue with the OEM LG unit as well. So now the Crystala unit is installed and working fine. After flushing, tasted the water and it tastes 'normal' as expected. Will save the LG filter for future exchange.

Note - with the LG unit and its packaging in hand, I was able to compare its and the Crystala specs side by side. Both are NSF tested and certified, and have the same temperature/flow/pressure specs. The Crystala unit listed as made in China, whereas the LG unit is listed as made in Mexico. Note that the "HD" HDX filter I was replacing is listed on its label as made in the USA, but its lug configuration is not the same as the LG OEM filter.