I have owned three sets of Sidis now, and as a norm, would say they are good for at least 2 1/2 - 3 years of use. The Sidi Vertigo Corsas I have now are just coming to the end of their life. Its the sole that wears through at the front that normally finishes them off....... I crashed big in the ones I have now, once on the Ring... and once, ahem, somewhere else... But they were fine. Did their job and just got a bit scuffed up.
Always comfy, and considering I wear them practically everyday back and forth to work, do trackdays and walk around bike meets then the amount of time they have lasted is worth every penny.
They are discontinued now, but you can still pick them up new on Ebay and the like........ Im just about to order a set of the new Sidi Vortice. Cant fault um !!!! tup1