Hebrew and Aramaic definitely get a special “so many frigging affixes that it takes half an hour to figure out the root before you can look up the frigging word in the dictionary” award in my book. I assume I would feel the same way about Arabic if I ever learned enough of it to even attempt to use an Arabic dictionary.
(I should note, though, that while Farsi and Arabic use the same writing system, they are from different language families.)
On the other hand, once you understand how to construct & deconstruct words, it's a lot easier to build your vocabulary.
You learn the word "read" & you immediately know all the verb tenses (read, reading), the nouns (food) the adjectives (written). Inconsistencies & exceptions make going from conversational to fluent a nightmare, but getting to conversational is not too bad.
Affixes, like an new alphabet are a bit of a hurdle, but once you're over it it's not hard any more.
(I should note, though, that while Farsi and Arabic use the same writing system, they are from different language families.)