The van seats were 28 years old, and starting to be uncomfortable - no support, and the covers were getting thin, so I bought some cheapie sets on Ebay while I figured out what to do about them in the long term.
The seats themselves aren't bad, but they're not great. They're more comfortable, I think, but I'm pretty sure they're not going to last anything like as long as the originals. The thing is they come with no instructions, so I spent half a day figuring out all the wrong ways to mount the sliders.