The Rosewill EX-500 is quite the interesting beast. In terms of build quality, it scores with its housing material, high quality wiring, microphone, and function button. Yet it is just a little bulky in comparison to what is out there, and it seems like the assembly process is not quite as spick and span as with the EX-700. However, that does not mean that it is a bad in-ear headphone - on the contrary. Its overall build quality is great for units of this price tag.
In terms of sound, you do need to turn it up ever so slightly higher to really get the full range to show itself, which those who like to crank their in-ears on the road may end up missing. But the sound is quite balanced, with the "treble tips" helping ever so slightly in raising the highs for that little bit of extra subjective clarity.
So for just under 40 US dollars, you get a very good set of extras and some worthy sound quality to go with that - all packaged into a nice, sturdy, and high-quality in-ear headphone.