Bests & Worsts Reviews from Amazon

I purchased this headset from a local store, not from Amazon, because I needed it immediately. But, I read the reviews here and I had high hopes that it would be a great headset for me. Unfortunately, while the headset has several innovative features and is comfortable and well made, two issues have caused me to return it. I should start by saying that I used the headset with the iPhone 4S. First, the good. The headset is comfortable and easy to put on and take off, although the large piece that goes behind the ear is difficult to put on while wearing my Oakley M-frame sunglasses (I have to move the temple on the glasses, put on the headset, then put the glasses back in place). People I called reported that the audio quality was very good. I like that the unit has real volume buttons and a real "answer" button. I like that it shows battery level on the iPhone's screen. I like that when you turn the headset on, if it's on your ear, you hear it report the expected talk time remaining via speech. Bluetooth reception was adequate. The proximity sensor is a great idea, and some aspects worked well. I *really* liked being able to answer a call or switch to the headset just by putting it on my ear. I will miss this feature a lot! On other headsets, I've had problems where I have been speaking on the handset, and I happen to walk through a room where my Bluetooth headset is sitting. When the headset comes into range, the call switches to the headset, and mayhem ensues. This headset won't do that, because it "knows" that it's not on your ear. Now, the issues. First, the audio is, in my opinion, trying too hard to be "HD". It sounds to me as if there is a substantial treble boost applied, so when listening to speech (either on the phone or via A2DP on a podcast), sibilant sounds like "S" are over emphasized and actually a bit painful to have blasted right into the ear. I think the audio would also benefit from some applied dynamic range compression, particularly on phone calls. When driving, if I turn the headset up loud enough to reliably hear the other party, those sibilant sounds are excruciating. And, when the other party happens to shift their own telephone so that their voice gets a bit louder, you really get blasted. Reducing the dynamic range would be entirely appropriate for telephone audio. Second, despite the great aspects of the proximity sensing feature, it is a bit unreliable, and also not well implemented for A2DP. I had several occasions where putting the headset down on a table caused the proximity sensors to believe that it was on my ear, and this caused paused audio from the iPhone to resume playing -- through the headset I'm not wearing. Result: lost place in my podcast. More bothersome, it continues to accept A2DP audio even when it knows that it's not on your ear. On the iPhone, this means that all iPhone audio signals like text alerts, key clicks, sound effects, etc, are sent to the headset sitting on the desktop, instead of coming out the iPhone's speakers as they should. This really completely defeats the purpose of the proximity sensor, and makes the only viable option turning the headset off completely when it's not in use (so you lose the proximity-based answering feature as well). I hope Plantronics may address these shortcomings in the future, or perhaps another manufacturer may implement a sensing feature. I will truly miss the parts of this headset that worked well, but I can't risk damaging my hearing with the blasting treble, and I'm tired of missing text alerts on my phone because the audio is not routed properly.