The most clearcut regional distinction between Esperanto speakers that I’m aware of is in the accentuation of compound numerals, such as dudekkvin “twenty-five”. In some countries they are accented as dúdek kvin; in some as dudékkvin. I read somewhere an early Esperantist saying, after a conference in Finland, “the Finns have taught us how to accent numbers”.
Other than that, the unwashed masses of beginners and eternaj komencantoj are no doubt speaking semi-Esperanto with heavy influence from their native languages; but the standard is consistent, and I’m surprised at the examples Philip Newton brings up (though they certainly make sense).
You could argue that the long-drawn-out and tedious debate about verb tense vs aspect was regionally based, with the atistoj mostly based in Germanic-speaking countries. As the argumentation of both parties was based on tedious casuistry over the Zamenhofian corpus, I quickly tuned out of the literature.