Having learned Japanese with kana & kanji from the beginning, I find it quite difficult to read sentences written in romaji (for example in some questions here on the SE). My mind takes forever to connect the intuitive pronunciation of the Latin letters with the corresponding Japanese word (especially with conjugated verbs).
I know this is a rather subjective question, so to narrow it down, I would assume someone, who knows a language that uses Latin letters (e.g. English) well enough to intuitively read them, but has had no extensive prior exposure to romaji specifically (e.g. for a job as a Japanese teacher).
Not sure whether this is appropriate for the meta or main SE, or even at all, so let me know.
Asking out of curiosity.