I had the same observations with toebox width on the Cascadias as well. The Cascadia 5’s were about the perfect toebox width. Unfortunately, all the EVA is worn out on my old 5’s and I had to throw them away. I still have a pair of 7’s and 8’s. These both have wider toeboxes than the latest Cascadia’s, but not as wide as the 5’s.
I don’t really understand why they keep narrowing the toebox. The Brooks Ghost 9 (the latest version) has a ROOMY toebox. I’m tempting to wear for backpacking, it’s so comfortable. Why do they insist on such narrow toeboxes for a trail runner, esp. when feet expand over long miles?
I haven’t tried the 12’s, but I did see the REI special the other day at REI and am tempted to give them a try. The Caldera’s look promising, but as someone else mentioned they are more voluminous (higher volume) than wide.
I tried on a pair of Lone Peaks a year or two ago and didn’t like the fit. It didn’t crade my foot well. I’m curious to try the new ones.
I’m glad to hear I’m not the only one who laments the ever-narrowing toebox on the Cascadia’s. If they would sell new 5’s, I’d gladly pay double. Someone please send this message to Brooks, as I’ve worn nothing but Cascadias for the last 6 years, and my 7’s and 8’s are almost worn out.