When I bought my S-MX, I wore them once to teach in July. By the morning break, I was already concerned about the wear on the soles from the hot asphalt. At lunch I went and bought a pair of workboots.
Since then, I've had just the heels replaced at a shoe repair place. He did a pretty good job of slicing off what was there and and attaching heel that looks and feels like it belongs. I don't wear them if I'm going to be walking more than I'm riding, and they've lasted several years. I've had to replace the velcro, and and it's probably ready again, but now I'm thinking of a different boot as well - perhaps the waterproof version. They've been very comfortable boots.
So i love the boots, but I haven't found anyone to put an Alpinestars sole on either, so I'm at the point of considering new boots.