I own at 21 LX and a 22 LX. (also, a 16 GX, and have had a 4runner and Tundra platinum in the past)
This new LX is certainly made in a more "disposable" manner. The seams (fender to hood, fender to door, door to door) are all slightly wider (2mm). The driver and passenger front door cards are barely held by clips at the top where you would rest your elbow (you can pry them off very easily, there's some play to them). Headliner is thinner, single sun visor per side (and it's flimsy at the clip when you lock it in). It does ride smoother than 21 LX and quieter (due to laminated windows for middle row, which previous model doesn't have, only fronts on that one). But man oh man, when you shut the doors on the 21, it's like a vault, on the 22 it feels cheaper, thinner, etc, but so happy that it has auto-close. The front bumper on the 21 has two horizontal supports (one steel, another is aluminum). On the 22, there's one aluminum bar and the other is a plastic honeycomb. The list goes on, I can make a video of them side by side someday.
Plastics are thinner, carpet pile is thinner. There is less legroom in middle row by almost 4in, it is perceptible (our GX has more middle row space). Slightly less legroom (maybe 1 in) in front, but not as noticeable.
The 21 LX is built better than GX, but this new LX build fit and finish is worse than GX.
Some positive: More power on tap, more nimble on the road and agile in corners, steering very light at slow speeds. Tech is great improvement.