Mark,
[font=Verdana,Arial,Helvetica]I went with Marathon cordura covers also. I put them on in 2010 and use my truck as a daily driver. Just yesterday when I got out of my truck, I noticed that a seam on the outside edge of the drivers side was starting to open up. The stitching is starting to fail at that point. I suspect this particular seam sees a lot of flexing from me getting in and out. the seat I'm sure has more give than the cover (no stretch in cordura) and the stitching takes all the stress.
Even so, I've been real happy with these covers. I've gotten them muddy and they clean right up. They don't stay wet or hold oders (at least not that I can tell).[/font]