Nero AAC gapless playback + other questions.

[Dologan]

Is Rockbox supposed to support Nero AAC gapless metadata? I'm planning to switch to Rockbox (again  ) soon and I am considering whether I should choose Nero AAC or Vorbis to convert my music to. Since the Apple firmware can handle AAC but not Vorbis and the longer battery of it could be handy for longer trips when I could just boot back to it for extra juice, I feel somewhat inclined towards Nero AAC, however, gapless playback is a must.
In any case, are there any other potential issues with Nero AAC I should be aware of? I think I had read a while ago that Rockbox had some skipping problems with high-bitrate AAC, is that still a problem in current versions? Are there significant differences between AAC and Vorbis battery life/CPU usage at ~ the same bitrate?
Thanks for your advice!

[saratoga]

I'd use MP3.  AAC gains you nothing, and it uses more battery.