I'm a US 10/EUR 43/275-280mm, and I sized down to 42.
I have two Achilles lows and I don't find them particularly comfortable (they're also my only pairs of BALLA sneakers, and the only pairs I've seen/touched).
Sneakers that use the same sole, do they feel much different? Are most using the same insole (leather)?
The comfiest sneakers I own are a pair of suede Lacoste lowtop velcro shoes, where one of the straps is conjoined like those Raf ones... too bad they're like 5 years old and I no longer like them.