While the FJ starts with the 120 Prado chassis and uses a lot of parts in common with the Prado, but it's very different from there. The wheelbase is about halfway between the 4 door and 2 door Prados, with a better ramp over as well as approach and departure angles. It also has a slightly different suspension setup with the wishbones at the front. Also, the electronics are from a later generation, with CRAWL from around 2012 or 2013. It's like a hybrid mid wheelbase with a 120 base and 150 updates internally. Make sure you get one that has CRAWL. CRAWL is like a 'magic carpet button' on sand.
But on the other side IMHO it's too small for long trips and more than 1 passenger, and not the prettiest girl in town IMHO. The Petrol has a reputation for reliability, and they last forever but it likes to drink, or does in Parado's anyway.