yeah rockbox is worth using alone for the .ogg support in my opinion as it sounds noticeably better than mp3 at lower bit rates (i.e. under 128kbps... basically 96kbps or lower)
but even besides that it's still a overall nice app and it's nice to know it's updated constantly unlike the original firmware

... and it's nice to know my player aint 'limited' as it's used to it's full potential instead of partially hanicaped with MFG firmware etc.... and the games are a nice little bonus to.
and it's also pretty much the reason i bought my Sansa e250 cause i knew i could store alot of songs it on cause of .ogg format.... so even though i only have 2GB memory.. it's sorta like i have 4GB+ now.
p.s. i accidentally ran into Rockbox on accident

... cause i was thinking of getting a new mp3 player cause mine does not like 1GB SD cards (im fairly sure it's a firmware issue on the player) and it was just slow etc to go through menu's so i was looking around on newegg.com for finding a good digital audio player for a fairly cheap price and i ran into the e250 and seen someones comment saying something like.. "does not run rockbox cause of v2 etc etc" and i was thinking to myself what is rockbox so i did a google search and found out it was alternative firmware and seen what audio formats it supports and right then and there i was like i gotta get one

... so i went to ebay and made sure i had a v1 player and then ordered it.... 47 dollars out the door for a refurbished... but it's basically brand new cant even tell it was used as there was ZERO scratches on it etc etc.