The Sandisk 250 is fine for music and it certainly is more affordable than the Iriver T60. I listen to audiobooks a lot where an intuitive interface for backing up the file is important and I found the Iriver better at backing up the file. So if it's music, go with the Sandisk 250, if it's audiobooks or both, consider the Iriver T60.
If you do consider the T60, because I never used this model, only the T10, read this review, which includes comment by a backpacker:
http://astore.amazon.com/epizenternet-20/detail/B000TRKB7Q
Remember, Amazon does not sell this unit, the only place is Ebay. Because the Sandisk unit is so common and inexpensive, you might want to try that unit out first. It also comes in a 4gb model (which I have too). If you end up liking the Sandisk, your hunt is over with.