Music Question: 320KBPS MP3 VS 256 KBPS M4A

This is something I’d like to get a knowledgeable opinion about, I downloaded some discographies of artists, and it has 320KBPS versions of a few albums I already have (pirated) iTunes copies of, my current sound system is trash, but I plan on updating it. Is the iTunes stuff good enough, or would they be worth replacing with 320 rips?
Thanks.
Answer #1
AAC is the most efficient audio codec out there, 640kb is used for 5.1 channel movies so 256kb for 2 channel is excellent.
Don’t confuse bitrate with quality.
Answer #2
AAC is the most efficient audio codec out there, 640kb is used for 5.1 channel movies so 256kb for 2 channel is excellent.
Don't confuse bitrate with quality.
Thanks for the response, that’s exactly what I needed to know.