1995 Honda Odyssey
1) About 23mpg driving in town, close to 30 on the highway at 70-80mph
2) Very reliable, the only thing I've had to replace were upper ball joints in 20k miles. I changed all the fluids when I got it at 140k, and it has a small oil leak that I can't track down, but otherwise it's great.
3) Headroom is one of those things you give up in a mini-van. I'm 6'5", so unless I buy a step or box van, standup headroom isn't a possibility for me anyway. I had to build a subfloor because it sloped from rear to front, and now it measures about 42" from floor to ceiling.
4) My daughter and I lived in it the last 2 summers for at least a month at a time without any problems. I personally think I would have plenty of room by myself after I remove the front passenger seat and make a few other small changes. YMMV.
5) I'm coming up on 3 years of ownership now, but I don't have any plans on getting rid of it.
6) Everything is a compromise. For me, the most important things were fuel economy, stealth, and reliability, in that order. When I bought it, I was planning a trip to Alaska which included a ferry ride up from Canada, so overall size was important as well (the cost of the ferry depends on the length of the vehicle). I spent a lot of time on the fueleconomy.gov website exploring different options, both mini and full sized vans, and from what I found there I ruled out all the 6 cylinder engines. I would have preferred a manual transmission, and I still occasionally think about converting it to one (Honda Accord has exactly the same drivetrain), but it probably won't happen. With the front seats forward, I have almost 7' of floorspace x about 44" wide. I have more pictures if anybody is interested.
Norm