When I first connected the HeadStreamer to my computer I was pleasantly surprised that it interfaced perfectly with no configuration effort. Since the short (18 inch) USB cable that came with the HeadStreamer carries only the unprocessed digital signal, and the output to the headphone uses the cable that comes attached (usually) to the headphone, there are no cable issues per se that could potentially degrade the sound.
Although there were no configurations for me to make the HeadStreamer work with my Windows 7-64 computer, the PC volume window tripped me up at times. Whenever the USB cable is disconnected and then reconnected to the HeadStreamer, the music player volume slider on the computer's volume window disappears. In such a case the volume slider on the music player application will still work, but to get the music player volume slider back on the computer's volume window I have to close the computer's volume window and then reopen it.
I knew before I ordered the HeadStreamer that it was small, but when I removed it from the box it looked even smaller - about half the size of a pack of Camel regulars. One thing I really like about the HeadStreamer which is also true of HRT's iStreamer is that it runs cool. So far I haven't detected any tendency for it to become warm laying flat on a table, where only the top and sides are able to act as heat sinks. I really hope this is a trend in personal audio, since I've bought laptop and tablet computers recently that get uncomfortably warm.
For those people who have been using the headphone jack on their desktop or laptop computers, and assuming that those computers have USB ports, they should expect better sound using the Headstreamer instead of the computer's headphone jack. The fact that the HeadStreamer includes both a DAC and headphone amp in such a small package at a relatively low price, suggests to most audiophiles that the HeadStreamer's sound would be of much less quality than the typical separate DAC's and headphone amps selling for 2 to 3 times the price of the HeadStreamer.
I don't own the more expensive separates myself, but I have the Objective2 headphone amp that sells (assembled version) for as much as the HeadStreamer even though the HeadStreamer is two components in one. And I don't hear anything to suggest that the HeadStreamer has lower sound quality than the Objective2, or that the HeadStreamer is less than a good upgrade to the computer's headphone jack for a bargain price. The actual improvement with my computers is a cleaner sound with a greater sense of "space" and "air" around the instruments. My experience in making that comparison taught me that I would not notice the difference immediately when switching from the computer's headphone jack to the HeadStreamer's headphone jack. But when you listen through the HeadStreamer's headphone jack for awhile and then switch back to the computer's headphone jack, that's when you really notice how some of the life goes out of the sound.
An important issue to consider when purchasing audio components to improve sound quality is detail, i.e. how much additional detail will be revealed in the music tracks by the new components. It's possible that a new audio component could reveal existing distortions in the recording in a way that makes them less pleasant to listen to, and some buyers may experience that dreaded feeling of "Uh-oh, I need to buy more stuff", or "Crap - this isn't working out the way I expected". I didn't have that issue with the HeadStreamer though - the sound was more revealing but less harsh somehow, and I don't know in this case whether that was intentional on the part of the designer, or whether it's a typical result of upgrading the computer's DAC and headphone amp.
Questions have come up in several places as to whether a typical computer's USB port can supply enough power to run the HeadStreamer's DAC and headphone amp, to provide good volume especially in the bass where the greatest power demands occur, and to have enough headroom to avoid clipping or otherwise distorting the loudest most dynamic music passages. The answer seems to be yes, since I have many FLAC format music tracks with a 96 khz data rate that have extreme dynamics which distort noticeably when sufficient power is not available. Some of those tracks that I've made 320k MP3 copies of for playing on the iPhone will not play on the iPhone at the full volume I prefer because of the extreme dynamics, however those same MP3's will play without clipping on the computer.
Looking at the HeadStreamer from the top, the grey end-panel on the right is plain and attached by 2 screws. The grey panel on the left end is also attached by 2 screws and contains the mini-USB jack and 3.5 mm headphone jack. Also on this end-panel are 6 LED's, and one of those will light up at any given time to indicate the digital music track's data rate (32 khz to 96 khz). I've read comments in a couple of places where people have said they'd prefer to have the headphone port and USB port on opposite ends of the HeadStreamer. I very much appreciate having them on the same end myself, so here's a vote for the current design!
The HeadStreamer is enclosed in a strong pebble-finish aluminum case which probably won't show scratches unless seriously abused. It feels fairly light for a metal box, and photos I've seen of the interior show what looks like a typical small electronic component circuit board, so there's nothing there to beef up the HeadStreamer's weight. Given the quality of construction and the very nice overall appearance, I'd say they got this one just right. In fact, the HeadStreamer's size is so perfect that I can wrap it in the small fabric bag it came with and throw that into my small shoulder bag without sacrificing needed space in the bag, and have it with me wherever I go. And since the HeadStreamer gets its power from the USB, it is ultimately portable. Just remember to keep a small USB to mini-USB cable handy.