Bit-rate is just one aspect of the audio-codec. Are you planning to stream the MP3 to regular stereo system or just use it on the phone? Here is an example, where bit-rate is the same, but one is Apple Loseless, the other is a MP3 of the same song. For example, see the differences. If I play both of them through a BillD C1/M500t MkII, I can tell the difference between the two versions. I use an Airport Express Gen 2 to stream from iTunes.