I have both an Iphone and a Touch but when I travel I do not take my Touch I take my SONY MP3 player and my bose earphones. If you want to listen to music at its best you would never choose an Ipod. (and thats a Fact)
The Zune looks dam good but music quality I have no idea
Wow, that couldn't be any further from the truth if it tried to be. Sony MP3 players are known to have incredibly weak headphone amps (usually 5mw+5mw @ 16Ohms, compared to the iPods 30mw+30mw @ 32Ohms). They're also known for coloring the sound, enhancing low frequency sounds to make it sound more boomy.
As far as headphones... Bose? Really? It's definitely a well known fact that Bose audio equipment is absolute junk. It's built poorly and sounds even worse than its built.
http://intellexual.net/bose.html Theres a good article on their speaker quality which applies to their headphones as well.
Head on over to Head-Fi. You'll find the majority of people there are pushing an iPod with some sort of TRUE (non-Bose) high end headphone. For me, I use the 80GB 5.5G iPod with Audio Technica ATH-A500s (imported from Japan before they were available outside of Japan). That setup straight out of the headphone jack sounds better than any other portable audio set up I've heard and blows away Bose multi-speaker systems that cost 10x as much.
True, unfortunately. iPods use inferior D/A converters (Apple loves to cut corners on things you can't see), they have a 78 dB S/N ratio which is worse than mp3 players from the likes of Creative, iRiver and - especially - Sony. I was really surprised when I bought my first iPod, started it up and heard a distinct power-up *pop* followed by clearly audible noise, it brought back memories from my old cassette Walkman.
Then again, who cares... mp3 is an anti-audiophile format to begin with. iPod Touch is great for so many other things that I don't really consider it an audio playback device... it's a handheld computer that happens to play audio.
Properly encoded MP3 and AAC files (either LAME 3.98.2 using -v 0 -vbrnew or Quicktime's latest AAC encoder) have proven transparent in listening tests. Meaning they sound no different than the original CD.
S/N ratios don't mean much either. Creative used to rate their players and soundcards S/N ratios and list it in their specs. It wasn't until they got sued and countless individual tests showed the real S/N ratios were sometimes inflated by as much as half did they stop.
Up until the introduction of the iPhone, Apple used the same Wolfson DACs that were found in high end CD players and DVD-Audio players. The people over at Head-Fi have practically universally agreed that the 5.5G iPod was the best sounding, and the new Cirrus Logic DAC based iPod touch 2G sounds about the same.
iPods that had "sound quality issues" had bass roll-off problems with headphones with low resistance. Basically if you have a set of cheap $10 Sony earbuds that had a resistance of 16Ohms, you'd have a problem with not getting car stereo style boomy bass that some people seem to expect. But if you had a set of respectable headphones there was no sound quality impact.
MP3 players are my thing. I love audio more than anything else. I've heard just about every MP3 player out there on many sets of headphones. I've yet to hear anything that can match or beat the 80GB 5.5G iPod or 1G iPod touch running iPhone OS 2.x or 2G iPod touch with a respectable set of Audio Technica, Grado, Koss (only the KSC-75), Sennheiser, or AKG set of headphones.
I will say though, that the Zune with the same set of headphones comes VERY close to the iPod. It just lacks the final little bit of overall detail the iPods tend to have. But if one doesn't own an iPod, a Zune is the next best thing. Creative's players just sound as awful and as bloated and boomy and fatigue inducing as their soundcards. iRiver sounds like mud.