I grew up without foot binding so my toes are straight and fan out wide. Thanks to that I have never had foot issues of any kind but I cannot find shoes that fit. I used to run in Instincts, but the latest version 3 has much narrower toe boxes with uncomfortable hard plastic toe cap that restrict toe-splay. When I was about to give up on Altra, this new version of One came out and it seems to work well. The One2.5 has a curved last with very wide toes with narrow heels, completely different from the Instinct's straight last with narrow toes and wide heels. The One2 had extremely shallow toe boxes that make the shoes effectively smaller even when the sole patterns are the same, but apparently Altra addressed that issue with the One2.5. When you compare the profiles of One2 and One2.5 you will clearly see that One2.5 toe boxes are taller almost by a half inch and thus more give to allow for better toe splay, but the fit of heels are snug so they do not swim inside like in Instinct 3. One of Altra's weakness has been durability so I will see how it goes (it does not feel any more durable though).  For me finding shoes that fit is so hard that I have to be content with just that, but Altra's inability to find the sweet spot and stay there is pretty frustrating. The great concepts (zero-drop, wide toe box...) have been ruined by some weird extreme changes between versions, and quality controls. At this point I have limited confidence with them and I will stockpile on One2.5 so I can weather another swing to the other extremes in the near future.