The OEM all-weather mats came with our 2018 as part of the Cold Weather Package, and they are fine. I've always been a "mats guy" rather than a "floor liner guy." I don't want to feel as though I'm driving a delivery truck, with my feet in buckets of plastic.
Nothing wrong with the Weathertech cargo liner. However, I ordered custom-cut cargo mats for both Cherokees from Lloyd Mats for two reasons: many more color options (I was able to order a pink one for my wife, although pink no longer seems to be an option), and a perfectly flat edge, instead of a raised, tray-like lip. I find that it's easier to slide things into the cargo compartment with the seats down if there's no barrier along the edge of the cargo mat.
