You are right about it being the same car. However several more inches of head room, several more inches of rear set room, at the expense of cargo space. So more creature comfort in the back seat. The GX is just much nicer to live in for adults than the 4 Runner. If we still had kids at home, maybe the 4 runner would be better. But want to take another adult couple out for dinner in one car, the gX is hands down better for that. I can ride in the back seat of the 4 runner, its not bad, I can ride in the back seat of the GX and its pretty nice. My hair (what left of it) touches the ceiling on the 4 Runner, and getting in and out of the runner, I need to watch my head. The gX has several more inches there. The GX has the added benefit of another gear in the tranny and V-8 power. It's certainly no torque monster, but WAY better than the 4.0 ltr. Not much gas mileage sacrifice either. Over all, the gX is much better on a road trip, especially for more than 2 adults. About the same as a Limited 4 runner on the trail. visibility out of it is a little poorer in the gX, and more plastic at risk. The GX gas tank skid plate only covers 1/2 of the tank.
So want a truck based tuxedo, buy the GX, want a cheaper version for kids etc, buy the 4 Runner. Yes the LX/Land cruiser is much bigger, but surprisingly the size isn't used as efficiently. So not a lot of additional utility. I would have prefer the Land Cruiser, but wife's daily driver, and she won out. The Land cruiser retains its value a lot better,so does the 4 Runner.