Is olfaction same among different individuals?
Humans generally have the same set up of olfactory receptors, since they are encoded by genes (there likely are minor differences between people, since there are a lot of these genes). Therefore chemically or physically  all humans can smell the same substances.
However, how a smell is perceived depends also a lot on how the brain reacts to a certain smell (or rather the activation of certain olfactory neurons). Therefore individual people can perceive the same chemical substance a different way - how different depends probably strongly on previous experiences.