GX470's are spectacular. Coil conversions are cheap/easy/common and solve the rear air suspension problems.
Come to the dark side- we have lattes! https://www.facebook.com/groups/LexusGXOR/ https://lexusgxor.com/
If you're planning on taking it off road, consider getting the rear diff in the GX470 rebuilt with a solid pinion spacer. A high mileage 8" rear diff with the OEM crush spacer is likely to fail eventually if ran hard enough.
Model year 2005+ for VVT-i / more power. It runs fine on 87 (but the manual asks for premium).
There are a few people in GXOR with over 400k miles on their 470's.