The LX/LC is wider than the GX, so squeezing into a narrow space is harder. The LX has a smaller turning circle than the GX, so that is a help. I drove a 4Runner for 13 years, which is a similar size to the GX. I was pleasantly surprised by the LC as it doesn’t drive “big”. That is, while driving it seems smaller than it is. The LC has very good visibility. I think the LX has bigger D-pillars, so that might hinder it a bit.
Stow the third row on both the LX and GX, open the rear doors and take a good look at the cargo space. I think you’ll find that the cargo space in the GX is disappointingly small. If you are going to take road trips with your family in a GX, you’ll need a rooftop box. With the LX you won’t need a rooftop box.
I used to use a rooftop box on my 4Runner. It was noisy and a pain in the neck to deal with. I no longer use it now that I have the LC.
I test drove the GX three times and was very close to purchasing one. I got a two-year-old CPO LC instead for the same price. I think the LC is a much better truck.