I also kept referring to that link (
http://macintoshhowto.com/itunes/which-ipod-has-the-best-audio-quality.html) before deciding on what dap best suits my needs, and recently decided that I should just go ahead with an ipod classic despite what the article says.
I haven't tried the 5.5 g ipod, but to my ears, the 2009 classic offered quite a reasonable SQ. Not the best, but still enjoyable. But then again, I was already planning to add a dac (fostex hp-p1) so SQ straight from the ipod was rather irrelevant to me.
I also auditioned a sansa fuze, which straight from the headphone-out does sound slightly better that the classic 2009, also straight from the headphone-out - at least to my ears. But, as I predicted not as good as a classic - hp p1 combo.
I suppose whether an ipod is good or bad all depends on how you plan to use it, your budget for amps, dac, earphones, etc., and most importantly, your ears and tastes. I personally don't buy comments/articles which basically says that ipods are bad and not worth buying, although i'm not a i-fanboy either. All I can say based on my experience, is that they are not bad, but ain't the best either. But, they are perhaps the only portable dap that allows us to use a portable dac (p1 dan clas), which in my opinion makes the sq of the devies rather irrelevant.
In short, the only one who can judge whether an ipod is good or bad is yourself
