When I first put them on, I thought they might be a little too snug because of the strap holding the tongue in place. Turns out though, the strength of the sides of the shoe combined with the strap in the tongue gives the shoe more rigidity than the original knits. Add in the thicker sole and I believe they are actually more comfortable than the original knits which were like walking around in slippers!! Also, the new ECO Knits are even lighter so now you have the most amazing shoe on the market! Highly recommend!