I read this yesterday, http://audioboost.net/2012/05/10/ipods-with-wolfson-or-cirrus-logic-audio-chip-which-one-is-better/ and thought it might help some that are confused because of lack of experimenting, etc.
Note: DAC chip details missing for iPod Touch 3G; 4G. Though, I think it's safe to assume they were Cirrus'.
Unless he's heard them all, those are very grandiose generalizations. They don't all even use the same Cirrus or Wolfson chips. A touch 3g LOD out is very smooth open and detialed, hard to beat.