My wife kindly bought me the 8Gb iRiver e100 MP3 player recently.
I chiefly liked it because it played FLAC files (lossless compression standard) natively without any hacking about.
Out of the box it had a few irritating problems including a very slow menu, crappy song seek, randomly ordered Artists/Albums and noisy buttons.
The firmware is easily upgraded via the iRiver Plus 3 software. When plugged in it detects your players firmware and offers to upgrade to the latest version.
Recently firmware upgrades have largely fixed the unresponsive menu and song seek is marginally better (but I might be imagining it). Nothing will fix the clicky buttons, but I live with that. Artists/Albums can be ordered using the iRiver Plus software, but why it doesn't default to alphabetically I'll never know.
Unfortunately the latest firmware (1.21 G_U) has a massive problem. The player has an option to "fade-in" songs. When the song starts, the song will fade from zero volume to full volume in about 2 seconds. The song will also fade out at the end.
In the latest firmware, when you turn this option off the fade-out turns off, but the fade-in remains. All songs fade-in regardless of the setting.
The vast majority of the music I listen to begins instantly, so fading in the song ruins the experience.
As far as I'm concerned the player is broken with this firmware, and if I'd bought it this way I'd have taken it back.
Unfortunately I can't rollback the player to an older firmware. An attempt to do so with a driver from the US website bricked the player, but luckily the Plus software was happy to install the new firmware again without issue.
The Australian iRiver help contact was quick to respond to emails and helpful (once I had managed to communicate the problem I had, initially they didn't seem to think the fade-in was a problem). They forwarded me on to the US contact who has not replied.
Hopefully the next firmware fixes the problem, but meanwhile I'm restricting myself to less intense music.
Update: I have since discovered the fade-in problem doesn't occur when playing FLAC files, only when playing MP3 files.