I have a Nokia 5800. I just listened to it with my IE8s and compared it to my Creative Zen X-fi.
First to ay I am new in this community and I think here are members, who could describe diffrences between these two devices better, because of their experience.
5800: present and nice
X-Fi: not as clear as the 5800
Here the two are similar. I can not hear much diffrence.
The 5800 emphasizes on the mids.
5800: some kind of thin, not good in my opinion
If you like Rap or RnB, you will not like it.
The X-Fi is very bassy.
Overall, the 5800 sound is detailed and more likely cold.
The X-Fi has a warm sound. The 5800 is still the best phone I listened to and I had a lot of music phones. It sounds much better to me than the Ipod Touch 1G, but not as good as the Zen.
Asus A6000>Sansa Fuze>Creative Zen X-Fi>Nokia 5800>Ipod Touch 1G> Archos 605
Ok, I hope I could help. Except of the SQ, this is a nice cell phone. It has a lot of nice functions...