We've got 265k miles on our '94 Astro. My wife has used it for 10 of those years on a 30-plus mile per day paper route, as well as driving it across country (literally) to dog shows, field trials, etc. I still use it as a daily driver to and from work (50-plus mile round trip) at anywhere from 65 to 80 mph.
The only major repair has been a transmission rebuild at about 150,000. Other than that its been the normal stuff like water pumps, an alternator, fuel pump and bunch of brake changes.
Watch for front-end steering components -- idler arms seem to be a high fail item.
It's been a fantastically reliable vehicle - and we've usually expected to see nearly 19mpg throughout its lifespan.
Mark