The shoes are pretty true to size but I said they ran somewhat small because the toe box is tight.  If you have arthritis and a bone spur your titanium insert won't fit, even if the sole is removable for the purpose of inserting an orthopedic.  They are very stiff on their own so I thought they might work without it so I did try them, and they are OK but I don't really like them.  The 3 separate air pillow cushion design gives them the curious trait of being super stiff and and the same time unstable.  I need stiff AND stable.  I bought them because the last shoes that I could wear were Reebok.  I kept them even though I didn't really like them and they hurt when I first put them on because I didn't think I could do any better, but I just found some SAS tennis shoes with a big soft toe box that ARE stiff and stable, like my very comfortable Birkenstock sandals.  But really, every foot is different.  If you have foot issues you can't go by somebody else's opinion, you just have to see what works for you.