As for native speaker, I can say it depends on people. I’m Japanese and a freshman, and almost all of my friends(They said,”I don’t like Kanji” although they are Japanese!)can’t recognize Simplified versions of traditional character(Or they don’t know Traditional character) I can say some (or most) young Japanese can’t.
So I cannot say it is easy for native Japanese speaker(Of course we have advantage,)
I love Kanji so much so I can guess by looking at common part of character between Kanji and Chinese character. But even I and we native speaker sometimes can’t recognized if Simplified characters is VERY Simplified. Like 「 丰(豊)」「书(書)」「 无(無)」「几(幾)」etc...