I hesitate to post in the 100s section, but here goes. I'll post about what I've said before. The 80 is unique. It's weirdly overbuilt in an old school way. Solid axles, full float rears, 6 x 5.5, straight 6 with all the torque down low. It's a dressed up utility vehicle. If you want to remember what Land Cruisers were, 50 years from now, the 80 is the one to keep. It, is a truck. Nothing will be made like this again (for the USA).
The 100 is a great vehicle, almost too good, it just isn't unique. Can you tell me it's that much different than a Tahoe? It's obviously better made, more capable, stronger etc, but it's just Toyota's vision of the same thing. I saw a guy at Sierra Trek in a Ford Expedition. It's the same thing, only with "legendary Ford quality". Toyota goes the extra mile with the 100, and I'd like the V8 in an 80, but the 80 reminds me of my 60 and it's Land Cruiser heritage, and the 100 reminds me of a Tahoe, only better.
Think about this-20 years from now, they won't be making 100s any more either. Are you more likely to see an 80 or a 100 at Rubithon? I guess I see the 80s aging better over time. To me, Cruisers get better every year they exist in the world, and I love my 22 year old FJ60, and my 35 year old FJ40. I just don't see myself feeling the same way about a 100, 30 years from now, even though I will likely own one during that time frame.
So is an 80 better? Not really. The 100 is faster, quicker, bigger, same or better fuel economy. For most uses, the 100 is better, a superior vehicle. The problem is, for most uses a CAR is better, or a MINIVAN is better, than either. It isn't about most uses. Instead, it's about balance. A fairly average 80 can take on the Rubicon trail, and drive home in climate controlled comfort at 80 mph. A well built 100 can take on most trails in Moab and drive home at 90mph. Where each individual exists on that balance beam determines what he will enjoy most in the long run.
So, flame away if you must, but remember, I like all Land Cruisers, and I have great respect for guys who own, drive and build 100s into their version of a perfect vehicle. Don't take what I say too seriously, I'm the guy who lets a perfectly good 80 series sit in the driveway and drives a 60 series every day because I can. For me, personally, I like the historical connection to the past that I feel was broken with the USA version of the 100 series. That may mean nothing to the original poster who asked the 80 vs 100 question for the 999th time.