I have a few yeezy’s. Here’s a few just for reference.
grey gum 750’s= Sz9
OG zebra, bred, frozen yellow =Sz9.5
See through stripe 350 v2= Sz9
500’s sz9
Waves sz9
azael sz9. Fits very snug but feel like it will break in nicely.
Alvah Sz9.5, too big for my liking. After breaking in it’ll feel way too big.
Made a similar mistake with my wave runners. Started with a 9.5 but after wearing them a lot they felt like a 10. Sized back down to a 9, at first they felt snug (not as snug as the sz 9 Azael) and now they feel perfect.
QNTM lifestyle I went with a 9 because I knew a 10 would be too big. I figured if the 9 was too small I could always take the insole out for some comfort. They ended up being the most comfortable right out of the box. The toe box is spacious and, you can move your toes. Can’t do that with the azaels lol. A 9.5 in QNTM’s would’ve been too big.
hope it helps.