How long an individual person’s shoes last has much to do with the terrain one walks, one’s gait, and how heavily one strikes a given part of the sole. I wear out the outer edges of the heels on anything very quickly, and I am very hard on the “push off” from my right big-toe area in particular. The dominant leg will wear out a sole more quickly than the non-dominant leg. If the mismatch is large, then your gait can be influenced fairly noticeably long before the sole has given up the ghost. A mismatched gait can end up causing pain.
That is why I have many pairs of boots and shoes for adventures that I keep for wearing no further than to the store or for puttering around.
So, now that I have the caveat out of the way:
I used to wear Keens for all my hiking, but they are hot and heavy. I switched to Altra Lone Peaks about 2 years ago and wear them for most hikes, and took them on two Primitivo walks and a San Salvador.
Each time, I take a pretty fresh pair that hasn’t more than about 70 miles of wear. They are good for the 367 K plus wandering about that gets me from Oviedo to Santiago, and did the 400+ that added the Salvador to the Primitivo. Both pairs have proven to have plenty of life at home for more walking, and I’ve only tossed two pairs of Altras for being worn smooth and uneven. I still have 2 pairs of Altra shoes and a new-in-the-box pair of Altra midrise Lone Peak boots (for autumn or winter on a Portuguese).
To the best of my knowledge, no trail runner or athletic shoe will say that it can go any further than 500 km without developing some problems. Does that mean the shoe is unwearable or broken? No… it just means the companies advise you to switch at that point for the reasons I addressed in P1 of this post.
Because I get zero blisters with Altras, because they are very light, because they dry very swiftly, and because the transfer no shock to my feet or knees, they are now my shoe choice for any Camino.
I am planning to take the boots to Lisbon in December and to go as far as I can between mid December and about Jan 5th… not 650 miles, to be sure, but pretty dang far with a person who is known to be very hard on her shoes.
Take from this what you like…