These shoes are ready to wear out of the box, no breaking in needed. I'm a cushioning maximalist and find these a little too hard for me without enough of the promised "bouncy PWRRUN cushioning" ; if you like a more grounded feel, these are the shoes for you. Good traction on roads and grassy parks so far. With the small lugs on the outsole and what looks like a rock plate, I expect these will perform in slightly rougher conditions as well.