Personally for me moving on from an ipod touch to Cowon player's was the best investment I could of possibly done for this hobby and often highly over looked in place of purchasing "more headphones" by most.
When you listen to an ipod it just sounds like music, it may be decent quality, but it's still just 'music' all smeared together. When you move onto Cowon players or other audiophile focused players all the instruments separate, you can hear everything individually own it's own within a track, all passages become highly detailed doing their own thing to make the song complete making tracks an absolute joy to listen too. Cowon players are also known for fabulous bass reproduction with Mach3bass not just 'loud' bass, solid, firm, detailed bass. I'll be honest your ipod touch bass is very average as is it is an average music player as is it's tone, and detailing.
You can't have good music without a good source. ipod / touches do not fall into that category imo.