My feeling is that once you have found footwear which works well for you you should not change it without good reason.
Completely agreed. Whether boots or shoes, the principle remains the same.
I've worn several generations of Brooks Cascadia shoes for about 10 years now, hiking all kinds of back country in the Rockies, as well as the
Camino Frances in 2013. I wanted to get footwear with a bit heavier sole for this summer's Camino because my feet were very sore after the accumulated daily punishment of walking, so I found a similar shoe from Adidas that had a thicker sole with greater cushioning. In most every other respect, they were identical, right down to the insoles. But, because of the soles, when standing on the same pointy sharp rock, the Adidas were much more comfortable. Mission accomplished!
BUT, on repeated 15+ mile training hikes, I got more blisters in three weeks with those shoes than I got in the entire 10 years with the Cascadias. I can't explain the reason for such a big difference in result, but I'm not going to argue with reality. So, tomorrow night, I have a new pair of Cascadias waiting at the shoe store. I'll take sore feet over blisters every day of the week, and twice on Sunday.
And, to those who argue that we don't really need to train to walk the Camino because we've been walking every day of our life, it's the little things that don't show up in daily walking that do show up in spades when repeatedly walking long distances. If I hadn't properly trained with my gear, I would have discovered this problem too late, and suffered needlessly because of it.