I have owned a Montero, and have wheeled with the FJ's, and have a drinking buddy who is the Toyota FJ Trail Team Leader.
I don't think the LR3 is better than the FJ in off roading. They are about equal stock, but the FJ can very inexpensively be modified to be far better. You can get a 3" lift and still be in factory warranty and spec, and 6" kits are now available. There are dozens of MFR's of front and rear steel bumpers with significantly improved angles, and skid plates and rock sliders aplenty.
The earlier FJ's required a software hack to enable the rear locker AND traction control at the same time (for the front wheels), so without the hack, the LR3 has much better traction in a given situation, but the FJ has good articulation, and good angles & clearances.
However, the LR3 is WAY more comfortable to go off roading in. It has FAR better visability, and It is SIGNIFICANTLY more refined, spacious, and comfortable. Also, the LR3 has a better turning radius, and a much more powerful engine.
The Montero (no longer sold in the US), has center and rear lockers available, and great angles, but limited ride height stock. Lifts are available, and turn it into a downright nimble little billygoat. They are quite nice inside and handle off road rigours well, properly equipped and slightly modified. They are hugely popular overseas, in their more basic trim levels.
There are some photos on my website of a joint Land Rover/FJ Trail Team trail run to the John Bull Trail in Big Bear, CA:
http://blog.nextstepdesigns.com/?cat=23