The Rockbox firmware provides the user with the ability to play a host of new codecs including ogg, FLAC, ac3 and acc. While ogg playback won't be anything new for iRiver users, this might be a very useful feature for owners of the iPod. An interesting addition in Rockbox is the seemingly smoother scrolling. At first I thought that this was achieved through some sort of algorithm. But after using the file navigation for a longer period of time, I determined that this effect is achieved primarily though having a smaller font (though a scrolling algorithm is also implemented) allowing a longer list of folders to be displayed in the file browser. I would like to note that the font size is dependent upon the theme and some themes might force you to revert to iRiver's default of seven folders (or whatever the number it is) per window. However Rockbox's navigation is slightly buggy and sometimes the player lags while loading folders with a large amount of subfolders. Hopefully in future releases this issue will be fixed.
Gapless playback is supported with ogg, though I wouldn't consider this 'a killer feature' of Rockbox. The Rockbox firmware cannot play WMA files or DRM enabled files (only applicable to US versions of the player), but considering the target audience of this firmware, this shouldn't be an issue. Due to patent issues Rockbox doesn't implement SRS WOW, which is a shame, but I think the equalizer compensates for this. The FM radio works fine and you can rip tracks from the radio, if you so desire.
One significant improvement in the Rockbox firmware is the playlist system. Rockbox implemented contextual playlists. So whenever you start playing one song within a folder, automatically a playlist containing all the tracks from that folder is created. If you want to, you can either insert tracks in your playlist or enqueue them (play them once). This is a significant improvement over the iRiver firmware which was limited to a 1 song enqueue system and lacked a method of creating playlists within the player.
Sadly I cannot give screenshots of the playlist system due to technical limitation of the emulation software.
The Rockbox firmware also supports a tag database that allows you to sort your music by artist, album, genre and even song tags. The tagging system supports both IDv3 and vorbis comments tags. It features a useful search feature for those of you who aren't good at keeping your folder structure organized. A significant advantage of the Rockbox tagging system over the iRiver firmware is that it allows for the creation of a database within the player itself. With the iRiver firmware, you had to create a tag database using your computer and the database creation tool was severely limited in that couldn't gracefully handle errors and crashed very often. Furthermore, it couldn't handle files that had a path longer than a certain mount of characters. This was significant problem for those of us who like to have a detailed and organized folder structure.
Rockbox's tag database.
While on the audio front things are looking quite good, on the video front things are not very satisfactory. Rockbox at present does not support any sort of video playback on the iRiver. This page suggests that video in some form is supported, but I couldn't find the video viewer plugin, my guess is that it ships only with archos specific version of Rockbox. The lack of video is quite disappointing, but to be fair I did not make extensive use of the video function on my iRiver. I am sure the Rockbox devs will implement video support at one point in the future, hopefully they will also make video support more flexible and support ogg streams and the MKV container format.
Rockbox's image viewer supports only JPEG images, but not PNG or GIF. However it does support the JPEG format quite well and the viewer is well designed and solves many of the problems of viewing images on such a small screen. Before the release of the latest version of the iRiver firmware, the default firmware would often choke on larger images. The Rockbox viewer has a nice zoom function and the slideshow mode can be quite useful. You can play music while viewing your jpeg files, but only if the files aren't too large, nothing can be done about this as this 'bug' is due to the hardware limitations of the player.
Rockbox handled my text version of Neuromancer just fine. The text reader is more flexible than the one provided with iRiver's firmware and the smaller font makes it much easier to read text files (usually it's the other way round, isn't it?) as the line lengths are of a more sensible size. The text viewer allows word chopping and word wrap to be disabled. Reading long text files becomes so much easier with the Rockbox text viewer. You can also load a text file from wherever you feel like, not only the TEXT folder. Like the iRiver firmware, you can listen to music while reading your text files and the viewer remembers your last viewed position, which is useful for long text files such as novels.