That's a fair question.
Of all the vans I've owned, one was a Mitsubishi 4 cylinder 1986 model (didn't like it...) two were 3.3 liter engines which both leaked oil like a tanker stuck on a coral reef, and the others were 3.0 engines. For the past 8 years I've worked as a courier, which is how I've done the majority of my driving. I put on about 50 to 60 thousand miles a year. 4 or 5 of these vans, including the two with larger engines, have been driven by my wife, who goes about 10 or 15 thousand a year. Ironically, she always has more mechanical trouble than I do. I buy almost every vehicle I own at the auction, some for as little as 50 bucks. Actually, now that I think of it, four of these vans came from private sales. But the point is that they always have over 100,000 miles when I get them, sometimes as much as 190,000, and I don't pay a lot. I put them right on the road and go. I have had the best luck with the 3.0. I'll have to admit that I like the water pump on the 3.3 engine, but other than that the two 3.3s I've had seemed like tired, greasy, noisy contraptions compared to the 3.0. Both of them had noisy valves, possibly even one stuck. I have done 3 water pump/timing belt changes on the 3.0, which really isn't that big of a deal after you've done it once. It isn't even that big of a deal to have a belt failure because the pistons don't hit the valves.
I don't know what you mean about the spark plugs. I have always changed spark plugs in the 3.0 by removing the air cleaner only. The use of a wobble socket helps in the case of the one under the alternator, but no major disassembly has ever been required. And I get great performance on $2 plugs.
I suppose that it's all subjective. I don't care what my vehicles look or sound like. In fact, I don't wash them because dirt is a theft deterrent. So I'm not into having a prestigious vehicle. I know you see a lot of minivans sitting at red lights with clouds of smoke wafting around, but when I go outside on a cold morning and turn the key, they always start right up and run, even if the valves are sometimes a bit noisy. Actually I have a suggestion for that, and your oil consumption problem. When you have an old engine that smokes and clatters, throw a bottle of Smoke-B-Gone in it and it will run as if it has only 90,000 miles instead of 250,000. I had one 3.0 that I drove to 275,000 miles, and it burned around a quart per 1,000 miles. Smoke-B-Gone cut the consumption down to about a quart every 4,000.