Not to derail this thread, but the only drawback, if you can classify it as such, is that memory foam behaves like memory foam. When you get up up from the seat, the seat does spring back into shape, but it does so slowly, like memory foam is apt to do. Kind of weird to watch it happen in a car, but like I said, after a moment, it does regain its shape - just not instantly.

I'll be happy to provide long term updates on these seats if possible, but it just goes to show that you can fix up these seats cheaply if you're willing to make some compromises. If one does use memory foam, I recommend looking for a used (but clean) pad on Craigslist. They tend to age well and are worthless used. I got mine for free. As it was going to be covered in relatively thick MB-TEX, I wasn't worried about using used foam.

For what it's worth, I learned the techniques I used from my father, who's a professional antique furniture upholsterer (not automotive) with over 50 years experience. So, I wasn't just futzing around - I did repairs that I knew had a chance of lasting for many years.