As for sound, it's pretty decent. I didn't find the Navigator quite as aggressive a headphone as the Aviator, so it's slightly warmer and serves up a good amount of bass without completely over-accentuating it. Detail is good but not great.
It's hard to pinpoint exactly what's missing from the listening experience for me, but there's a weird little hole in the top end of the bass, so I didn't get that loving feeling. That said, I was willing to put up with it because I liked the fit and finish of the headphones.
If you're looking for something that sounds better in this price range, there's the Audio-Technica ATH-WS55. Also, the over-the-ear Creative Aurvana Live is a notch up in the sound department. However, neither of those models has a built-in remote/microphone.
While I've heard some very good headphones for $99, I usually don't expect too much from sub-$100 models. The Navigators sound decent for headphones in this price range; they're just not up to the level of the aforementioned Audio-Technica and Creative headphones.
But the Navigators are more comfortable than the Audio-Technicas and have an arguably slicker design. They also have a smaller form factor than the Creatives, which will be a plus for some people.
In short, though the Navigators allude greatness; there's enough to like here to make them recommendable.