This bluetooth headset works very well, is clear and sharp on both ends of the line, seems to be insensitive to background noise with the exception of something high-pitched (am told that the popping and crackling of frying an egg makes all speech unrecognizable). It is quite comfortable over the ear, and I'm happy with that option since "in-the-ear" is ridiculously uncomfortable. But it comes with both those options.
Part of the productivity series, Oasis is the most comfortable and lightest behind-the-ear design. It has dual-mics and an extended boom for superior noise cancellation. Easy to use call button, dedicated mute button and audible voice prompts tell you when your are connected, which phone is ringing and battery level.