Sound qualityI'm no audiophile, probably nothing to brag about, but the sound quality is good enough for me. Very close to the sound you get on a PC with "average" speakers and sound card. I can't put my finger on it, but the provided headphones sound "tinny", so using a better quality set ought to take care of that. Max volume is more than enough in quieter places, but on a "rickety" subway like the older NYC trains, you'll be almost hard pressed to hear much of anything.
External controlsThere 4 controls: play/pause (technically play/stop, as when you DO "pause", it actually turns off while remembering where you last were), skip forward one track, skip back one track, and a volume jog dial control. The first turns on and plays the player, or pauses and resumes play. The next two are self explanatory, but further adding that reaching the first or last track will wrap around to the last or first track respectively. Unlike many CD and mp3 players however, there is no search mode available (done by pressing and holding these buttons). The last controls volume, but also can be depressed (like the wheel of a scroll mouse), which will automatically bring up the control screen regardless the current state of your Visor. The jog dial gets you to your desired volume setting after a few flicks, but the controls are just rounded knobs, so you'll have to press hard or use your nail. Also, you may accidentally lift and pull out the head phone jack (mine plugged in wasn't snug, but a little loose) when you try to press the button next to it. It has it's faults, but is still a nice alternative to having to whip out your stylus and cover just to control the audio. One thing I do like about this is the play button will light green (dim or bright) if you set it that way. This takes more battery power, but I recommend it so that you can tell if the unit is on or off, without having to turn the screen on or plug in headphones to listen and potentially draining your power without knowing it.
Software interfaceIt's simple and intuitive. Similar to Winamp minus the skins and fancy equalizer. You can bring down a pull down menu of all the songs you've loaded, there's an simpler equalizer where you can adjust bass, treble, and general frequency settings (none of which I really used), sliders for volume and track position (volume adjustable through the up and down keys as well), options to view details of mp3 tracks, and set modes of play (repeat, shuffle, etc.), as well as oversized standard buttons for play, stop, etc.
Loading musicEasy enough. All you need to do is ensure that all your music files are indeed mp3 format, drag and drop, and your next hotsync op will transfer the songs over. On the desktop software, it even tells you how much space you've got left before you transfer. Takes about a minute to transfer the full capacity. Pretty reasonable considering it Is USB 1.1.
Stability/reliabilityReliability has been good. I've never needed any tech support, and the thing's never broken down on me before. There have been times where upon plugging it in, I get "module was inserted improperly" or "Module seems hung, please try again". I sometimes get that once or twice in a row. The only time I get it 6 times in a row was when I left it in the car for weeks, in 35F degree weather, which I guessing was due to the cold.
Tech supportN/A as far as I'm concerned. The company is still there, but they've changed their business model. I tried calling them up about months after they changed their ways (this was approximately around summer of `02) and only one guy was there who had a decent understanding of what this product is and does. He wasn't able to answer my question though. Don't count on getting ANY tech support. IMO, this product is well made, so assuming there's nothing wrong with your Visor, tech support won't be needed.
Other notesFirst, you can play games, take notes while the music is playing simply by hitting the home button. You actually need to hit the `stop' button either internally or externally to actually turn it off. You could also leave the screen off to save battery. Next, you don't have the option of rearranging your playlist on the handheld. You need to do that before you load the music on there. Finally, only 64MB of nonexpendable memory? That makes this best suited for workouts, grocery shopping, and "low-end" users. 128MB would've been IDEAL. 4.5 stars is my actual rating, since there are some trivial issues with this, but it does deliver what it says smoothly and acceptably.