The reason I bought a T9 was mainly that it plays OGG Vorbis (but only under the UMS firmware, not under the -- default -- MTP firmware) and has a built-in FM radio, otherwise I probably wouldn't have taken this player into account and would've gone straight for an I-Pod, a Sony or a Philips player.
Design & UI: Since having this player, I have begun to hate Samsung's device and interface design (this is just my personal opinion). On the bright side: the navigation keys may require some learning, but are easily usable afterwards and the menu navigations is very logic. The only UI objective UI quirk I found is the overly small font for the clock (this shouldn't matter too much, because the clock seems to reset itself on a regular basis). Overall,
the player is very robust -- this excludes the side buttons (that just don't feel reliable) and the (easily scratchable) glossy surface. The screen is of acceptable quality, however, it can display a smaller amount of colours than the average computer screen.Music playback / library: As far as I can tell, sound quality is above average. The device has an equalizer with many available preset modes. When playing music, some basic visualisations or cover art (if a JPEG file of a defined size is contained in the music file) can be shown. The music library is not great: at times it misreads tags (maybe because it doesn't support Unicode tags). The library updater functions of the MTP and the UMS firmware differ vastly:
The MTP library updater only incorporates changes (which can render the library corrupt at times), but runs automatically after disconnecting the device from the computer
The UMS library updater can be used from the device's option menu (this only supports WMA and MP3 tags) or from within Samsung Media Studio (which additionally supports OGG tags and cover art; software available only for Windows)
Video: Because the maximum capacity with which the T9 is sold is 8 GB, which most users will use for music, the video function remains a gimmick. The only videos playable are DivX-Avis created with Samsung Media Studio. As the frame rate of videos is as low as 15 per second, movement does not look smooth. The videos are crisp, however.Photos: The player has an acceptable, albeit slow photo browser with slideshow and zoom functions.
Games: Three cheap Flash games are installed (none is particularly fun to play), in newer firmwares additional games can be copied to the "/Game" folder and then be used on the player.
Radio: The device has a nice radio that even incorporates automatic channel search and RDS, the only downside is that (due to the tiny antenna hidden inside the device) reception is not always good, especially when one is moving.
Voice / radio recording: satisfies expectations of such functions in an MP3 player; voice recording is really just made for voice -- I was impressed with the quality of the small microphone, though.
USB connection, charging, accessories: the player is connected to computers using a proprietary Samsung USB plug (which makes it hard to ever find a new cable should you lose the one coming with your player). When connecting the T9 to a computer it always begins charging (which takes about four hours to complete -- a resulting battery uptime of about 25 hours seems more realistic than 30 hours); there is no good way to connect the player to a socket -- generic power-plug-to-USB chargers are incompatible. The player doesn't come with any extra accessories and I haven't found any specifically made for it.
Samsung Media Studio: ...is another software for the category "hardware manufacturer's failed attempts at writing software". But still: the Media Studio is almost usable, compared to Sony's Sonicstage (which I had to use before). If you neither absolutely need video nor OGG files on your player, don't bother to install Media Studio.
Compatibility: Under Windows most everything is fine. Under Linux, the MTP firmware doesn't work with Rhythmbox and Banshee (it is possible to use libmtp directly, though), so using the UMS firmware is recommended. With the UMS firmware, two devices are erroneously shown in the file manager, which is confusing, but doesn't have implications on functionality.
To conclude, Samsung's player does much, but little perfectly. If you want a more pleasant MP3 player, consider buying an I-Pod, if you want a more compatible player (to both Linux and OGG), consider buying a Cowon or Meizu player.
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