Yeah I agree, somehow Borges's Spanish seems more accessible to English speakers, maybe because he was fluent in English as well. But my Spanish isn't good enough to tell if his writing is significantly different from other Spanish language writers.
As a Spanish native speaker, I would say he’s quite accessible. Most of the references he does are universal classics and he uses a pretty modern language most of the time. And he doesn’t do much playing with metalanguage.
I’d say.. the hardest to translate and read would probably be the most experimental just because there’s a lot of meta-references.. kind of like Joyce in Finnegans Wake.
Of course I understand the impulse, but translating Finnegans Wake strikes me as nearly impossible and worth only questionable effort. Even beyond the fact that it's often expressing non-analytic semantics that are extremely difficult to pin down, it's not even entirely English and there's a lot of cross-language wordplay.
I would add that a lot of Borges' work is written in an academic style that is highly translatable, but he also wrote a lot about the criminal underworld in Buenos Aires and those works are, unsurprisingly, full of slang and local references that are much more opaque to outsiders.
