Need some help, D2 - IPOD ... - sandisk.. arggh

[FIN23]

Ok in need of a new MP3 player..

Have been an owner of the X5, zen vision M and just returned the CLIX2 as it does not have any bookamrk feature and is vastly overpriced.. anyway, for the first time i find myself tempted by the nano.. purely because its just a player with a niceish screen.

The D2 looks very tempting also but i am concerned over the size of it, i want it to sit in my jeans without causing to much grief. Also like the look of the Iaudio 7 but it seems to be a bit of a lump... right my questions..

I rarely watch Videos (laptop for that) need a bookmark function for audiobooks and i do not subscribe to any music services.

1) Why not an nano? (i have never owned ipod) can it be used in UMS mode?
2) anybody got a pic of a D2 with a comparison item? (credit card or summut)
3) Can an ipod be browsed in 'file tree' mode or does it HAVE to use ID3 tags?
4) does the Iaudio 7 display album art? and has anybody got a piccy?
5) What player would you recommend at this time? flash or hdd money not really a problem as i have £180 credit at AMP3 due to the clix return. Looking at the Cube also.. need some guidance..