I bought one , its a really slick player. The jacket search (read cover flow) function is clever, the album art is very small but when you flick through them it plays a random part of the song/songs - genius.
Sound quality is top notch , my friend has the older e005 model and the e015f sounds much much better, clearer, louder, NO HISS and has smoother bass.
I tested the battery and got 26 hrs using a mix of 128 - 320 mp3 and 32 hrs from Atrac 132!.
The shuffle modes are cool , artist link , sports (timed), 100 fav and time machine (random year picked).
Oh the FM radio is very good also, i got it for £50 - 2gb fm.
When you consider this is a few pounds more than a shuffle you realise what a bargain it is.
The only negative i can find is that scrolling through artist/album lists is a wee bit slow.
Oh and for the guy looking at the sansa express, dont it sounds very mediocre , i returned mine.
The cherry on top is that Sony have announced they will be making these players play for sure soon.