I have seen one at the Hammers a month ago. The sucker would really run. But without beefing up everything ont he FJ it is too much for the really tough trails it seems to me. I know he snapped a cv joint and the ring in pinnion in one fatal swoop. Too much hores power for the ring and pinion is what I was told. Upgrades galore.
But it you are just doing the normal trails it would work fantastic is my guess. He said he did not notice any difference in mileage. But I know he was on it all the time. It sure sounds good.
I have though about it and was actually ordering one, but after the hammers I have decided that it is last on the list. A SAS front end is needed far more for what I like doing.
i don't own one, but i did drive one that TMS in Torrance was testing before they were released (manual tranny). i only drove street, but i would agree with skersfan: probably not much advantage for crawling, but if you like to tear down desert trails and washes, it would be cool. i prefer crawling, and would rather spend the $4K on other things.