The domestics can definitely find a place in the overland arena, and you have a point about parts cost and availability. It's a good thing they're easy to be had and that they're cheap, since you'll likely be looking for parts frequently.
All kidding aside, there are some decent domestic 4x4s, there just isn't one that "speaks" to me. The only exceptions would probably be an vintage Ford Bronco, or a vintage IH Scout.
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As for the LC100, I've had quite a bit of time in those and they are fantastic. In many ways I think they are the ultimate overlander. Powerful, comfortable, capable, roomy, reliable and even luxurious. Truly they are difficult to find something to complain about. We even looked long and hard at a LC100 as we considered our recent cruiser purchase. At the end of the day, we stuck with the LC80 because there is just some kind of emotional connection that I feel with the LC80 that I haven't ever felt in a LC100. The 80 is probably more capable than the 100 but a little down on power and the IFS in the LC100 is outstanding at higher speed overlanding. Also, since I had a built 80 already, picking up another one instead of a 100 meant I could pull all the mods off the old 80 and have a new built 80 at no extra cost. That was what made the final decision.
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If you are looking for a more roomier alternative to your Pathfinder, a LC100 will blow away any domestic option. It may cost a bit more for the LC100 at initial purchase but will require less repair and maintenance in the long term and as a result possibly cost you less over it's lifetime. If I didn't already have an 80 to pull parts from I would have likely gone with a LC100.