Got these to replace my Superior 4s, which I LOVE. Most Altras are too tight for me. My feet need space, and don't like to be squeezed sideways. They get grumpy. The Superior 4s have been amazing, like spandex for your feet. I was hoping that the 4.5s would be the same. They're quite a bit more rugged, so the 'spandex' doesn't quite have the give the 4s have, but they're still good. I've just had to put a lot more work into breaking them in and stretching them out. Still months later, they're way tighter, but I can manage.Overall, the Superiors are FANTASTIC shoes. Love them. Just know that if you're looking for 4s, these 4.5s will be a little bit beefier.