Just some observations.
I've wore 12M Dexter's for years and just a few weeks ago got the TPU-X's.
Before I bought the TPU's, I tried on a pair a guy here had we are the same size. They fit nice and comfortable.
The new ones I got felt snug and slightly narrow at the toes (mainly on the right foot) compared to the ones I tried on.
As I have wore them, The snugness is starting to go away some. I'm guessing they are starting to conform to my foot shape. (The padding in them is pretty thick too)
Comparing them to my SST's , as someone else said. Dexter's have like a clown shoe toe, meaning a boarder toe compartment. The TPU's have a toe compartment more like my gym shoes.
That's why they feel narrow toward the toes IMO.