I can't speak for the 4Runner but a few things I am sure GX 460 Luxury has as options 4Runner Limited does not. Correct me if 4Runner now has this
• Higher tow rating
• KDSS
• If it doesn't already have Crawl Control you can add cheaply as well as MTS
• Rear AC/Heater unit / 3 Zone heat/cooling with rear temp contols
• Powered 3rd row / They can also power tilt back/forward when rear passengers are seated
• Subjectively I've heard some comment quieter & more composed ride on highway. The KDSS really helps in corners
• Both front seats are 10 way powered.
• Rain Sensing Wipers
• Heated steering wheel
• Headlight washers
• Power folding mirrors. Stock they are manual but a $50 OBD dongle makes them fully automatic and they will fold in when locking car. Auto out as well
• Power tilt/telescoping steering column linked to seat memory
• Auto dimming side view mirrors
• 17 speaker Mark Levinson Stereo
• Genuine wood trim throughout
• Semi aniline leather
• three way adjustable damping shocks
• Auto smog detection by HVAC ( closes off the outside air)
• 12 Interior grab handles.
• 10 interior airbags
• LED Headlights (auto leveling)
• LED Fog Lights (auto leveling)
If it had Driver Support Package it would have things like side and front camera, radar cruise, Lane Departure, intelligent high beam, pre collision.
After adding the Crawl & MTS I'm now working on adding the side and front camera system on my GX.
2016 GX brochure
http://www.lexus.com/documents/brochures/2016/Lexus-GX-Brochure.pdf