I really like Saucony Guide's and have worn them for 7 or 8 years. When Saucony was my sponsor I used to push the shoes to 700 or so miles and they still felt fine and were holding up. I replaced them as a caution and it wasn't a concern since I got more of the shoes than I needed/
Recently it seems the durability has declined. Or maybe it is also partly driven by the change in lacing design, but now by 400 miles, the shoes are starting to fall apart. I get rips in the fabric, the fabric covering the heel plate is torn open and can start to rub on the heel. Even had one of the pairs where the thread was completely worn off. Not great since I used to get twice the distance out of them.