Tbh, I am beyond distraught with the sizing. Usually 9.5 in any and all UBs, so I went with 9.5 in the 4Ds. Bought 10s as a back up.
Lo and behold, TTS is way too tight and my toes literally hit the toe box in the front.
So I go with 10s and after a test walk yesterday I gotta say that they are tight (which I kinda like), but a bit too much so maybe. The left shoe is okay, I have about half a thumb room in the front and the tightness is fine. The right shoe is off, I got blisters on my heel (first time that ever happened in a couple of years) and my right toe keeps hitting the front of the toe box when I walk (I can feel it) even though when my foot sits still it fits the same way as the left shoe.
Not sure if I should size up again, as I feel like that would be way too big, but man, this experience has been so disappointing so far. Especially since I've been waiting for these for literal years and they are supposed to replace my daily 3.0 UBs that I've been abusing for 4 years straight