The Asolo TPS 535 has been fitting true to size, when the foot is measured wearing a boot sock using the Brannock device and the US sizing scale.
Also, it is a medium width, C/D - D(note that in Italy, there is a wide width available. Only the medium width is imported into the US).
If your foot does measure as a 9 medium, then it is likely the best choice.
Forgive the technical answer, but "regular" is a qualitative term in boot fitting and means something different to every person, it is not a scale.