What posture does herodotus take toward these differences? he does refer to persians as "barbarians", but at the time that term may have meant simply "non-greek", without the implication of "savage" or "uncivilized" that it later a?

For Greeks everyone who was not Greek was a barbarian, that's what the word meant. Herodotus was aware of how civilized some countries were but regardless of that they were still barbarians because they did not speak Greek nor were Greeks. He is honest in his writing and just notes down differences historically.