Product review (4 stars): Good Tasting Water
When looking for a lower cost alternative to the LG OEM water filter I came across the Waterdrop WD-LT700P replacement water filter.  The filter was shipped quickly and arrived undamaged, the filter itself was sealed to prevent contamination. I installed the filter just as I would the OEM filter without any issues. I ran about 2.5 gallons of water thru the dispenser to clear the system and charge the filter.  I then tasted the water and it tasted pretty good.  Other than taste I looked at the Ice cubes the next day and they appeared a little clearer to me. .  I have no way of testing the water for chemicals and such.

According the insert that came with the Waterdrop filter it states that "this filter is Tested and Certified by NSF international against NSF/ANSI Standard 42".
The LG OEM filter that I normally buy states its filter is "Tested and Certified by NSF international against NSF/ANSI Standard 42 and Standard 53". It also come with a California Department of Public Health certificate.

For references:
NSF/ANSI Standard 42 (aesthetics) applies to these contaminants: Chlorine, Chloramine, Bad Tastes, Odors, Sediment.
NSF/ANSI Standard 53 (health effects) for the reduction of specific health-related contaminants, such as cysts (Cryptosporidium, Giardia, Entamoeba, and Toxoplasma), lead, and volatile organic chemicals (Pesticides, Herbicides, or Insecticides)

Conclusion: I think the Waterdrop WD-LT700P filter does what it supposed to do, provide clear, good tasting water.  If I had any concerns as to other issues with my water, I would buy the OEM filter.
Disclaimer:  I did receive this product at a reduced price for my honest, well-thought-out and unbiased review.