The Plantronics M55 supports the A2DP profile, so it can stream music, podcasts, or other audio from your smartphone. This sound won't be in stereo but it'll serve if regular headphones aren't handy. Thanks to multipoint technology, the M55 can also link to two Bluetooth devices at once.
On my test calls, the Plantronics M55 held up well. Pairing with an HTC One S (T-Mobile) phone was a simple and quick process. I just switched the headset on, navigated over to the phone's Bluetooth settings, and paired and connected the two devices. The M55 announced that I was "Connected to phone 1" and I was off to the races.
As you'd expect, calls made in the office or quiet conference rooms sounded best; callers couldn't immediately tell I was dialing from a cellular phone. Voices on my end under these conditions came through loud and clear as well. That said, call quality improved when I switched over to using the handset.
Though Plantronics claims the M55 is designed to reduce wind and other background noise during calls, callers reported there was a faint but noticeable hiss when I used the headset outdoors. To be fair, I placed calls from busy New York streets bustling with traffic, construction, and other ambient din. I suspect that if the M55 came with dual microphones like the Jawbone Era has, its noise-cancellation performance would be much better.
One of the most interesting features of the M55 is what Plantronics calls DeepSleep mode, which is designed to hold a charge for as long as five months. Essentially, the device will enter a kind of hibernation when the headset is away from your phone for more than 90 minutes. Otherwise the M55 is rated to offer up to 11 hours of talk time and 16 days of standby time.
If you're looking for a compact, capable Bluetooth headset, the $49 Plantronics M55 should be on your short list. Though it doesn't provide the level of noise reduction and sophistication of the more premium $129.99 Jawbone Era, the M55 does have basic voice prompts and vocal commands plus an elegant look that helps it stands out from the budget headset pack.