recommended audio format

[sugargenius]

I'm setting up a Sansa Clip+ that I'll use only noisy environments (plane, gym, etc).  My music collection is all stored in flacs.  I was planning on transcoding to mp3, ogg, or m4a at around 100-120kbs.  Is there any reason to prefer one format over another from a Redbox perspective?  Are some formats "harder" to decode and might consume more cpu/battery?

[saratoga]

There are benchmarks for the Clip+ here:

http://www.rockbox.org/wiki/CodecPerformanceComparison

As you can see MP3 is actually a little bit faster then Vorbis or AAC at these bitrates, mostly because we run the memory very slow on the Clip+ to save power.  Vorbis and AAC like faster memory. 

[sugargenius]

Thanks!