We considered the FUSO for a long time. I think they are a very good option. I think the "right" truck is a bit dependent on each person and how they plan to travel. I think a FUSO is perfect for many people.
For a while I really wanted a Steyr 12m18. I drove a Steyr, and it was sweet, but they are ridiculously expensive to get in the US, they can be hard to register in some states, and I couldn't find a realistic parts supply.
In the end, we decided on an M1078 LMTV. The M1078 has some shortcomings for sure, but nothing is perfect. I like that it is over built. I'm pretty sold on it for an expedition truck platform. It's hard to beat the price of the base vehicle. The engine doesn't worry me. If I have trouble with it, I'll fix it or replace it then. There are many CAT shops around. The drive-train needs a little care I think. I've inspected my driveshafts carefully, and one is a bit out of spec for slop. I'll be replacing some parts of that driveshaft. It's not a big deal to do. It's a 20 year old truck, so I expect that kind of work and maintinace.
The mileage of the FUSO would be nice, but I have friends with LMTV that average 7-8 mpg loaded up. For what we plan to do, that fits into our financial plan.
I've heard some people say that the Steyr 12m18 gets like 21 mpg. It's not true. They get about 8-9.5 mpg. They are good trucks though.
Michael