Hi,
I just spotted this thread. We've had an '88 Toyota Odyssey in the family since new. My parents used to pack us up for two months at a time over summer vacation and cross the US, venture around Canada and explore Mexico. We didn't go South of Mexico but we had a lot of great miles. These days it's more of a weekender but it's still pretty frequently used in the warmer months.
It is a 2wd 22' with the 22R-E, 4-speed manual and full-float rear axle. It's done lots of washboard dirt, a little sandy two-track, Baja dust and Chaco mud. It's been really trouble-free. The engine hasn't required anything beyond fluid and filters. It's only needed a drive shaft, exhaust plumbing and brakes. It's on its original timing chain and clutch. It used to melt a distributor cap now n' again but epoxying the rotor on took care of that.
The chassis is very stout. We've hit some big bumps (topez!!) and haven't broken anything (just bruised some tailbones). It also has respectable ground clearance--more than most cars. The suspension feels very heavy-duty. It has some massive leaf packs in the back that don't deflect much, making for a rough but well-supported ride. I used to think the 4wd ones were cool but I've since changed my mind. They were pretty high-up and clumsy-looking. And I wouldn't want to add the extra weight. I prefer a manual transmission, especially in heavy, underpowered things. If you're off-road with an auto and the tires get in a hole, you can't do any more than hold the pedal down and listen to the transmission slip. With a manual, you can always rev it up a little higher and roast the clutch a little more to get that last bit of oompf.
The cabin has held up pretty well too. All the appliances and systems are original and work pretty well. The only problem areas have been a leaky roof and a little rot in the sidewalls and floor but nothing too troubling yet. My parents really like the floorplan--it has a side-bath so that there's room for a large seating area in the back with large windows all around. They rarely see other campers that they would be interested in.
It is fairly tall and wide but it's managed to fit everywhere we've taken it. It's done a little self-clearancing (the roof rack on a tree and the entrance step on a curb). The wheelbase isn't overly long, so with clever use of the rear overhang, you can usually park in most parking spaces. Fuel economy is certainly nice for its size--16-19 mpg. We used to sleep 6 people in it regularly, but lately it's been no more than five, since my sister and I grew a fair bit.
The Toyota C's are certainly aging but I think with careful selection and pre-trip maintenance/attention, I think one would make a great rambling platform.
For comparison, I have a pop-up truck camper on an '85 Toyota 4wd compact (it was certainly inspired by the Odyssey). While the total weight is a bit lighter, it gets similar fuel economy and has much less space. The rear axle seems much less supportive than the wide dually 1-ton axle under the Odyssey. The Odyssey even corners better, even though it's taller and has roof A/C, likely due to the wide, dually rear axle and mega leaf-spring packs. For going down the road, the Odyssey just feels better than my smaller combo--it just drives and handles nicely...and you can bring a lot more stuff and people!