After using the Jabra BT800 Bluetooth headset (see my review: http://www.epinions.com/content_183614148228) for over a year, I finally decided to replace it with something better. I settled on the Plantronics 645 after some research.

After using it for a day and a half, I became absolutely convinced that the Platronics 645 was the best Bluetooth headset hands down,

Physical Appearance:
The unit itself was sleek, small and LIGHT. It is slightly larger than a AAA battery and just about similar in weight. The unit comes in a very attractive chrome finished carrying case with 3 silicon ear pieces, charging holder, 4 recharging tips, a wire ear loop and the ingenious AAA pocket charger. It has a certain James Bond quality to the whole package - very sexy, very sleek.

Pairing:
The pairing between the 645 and my cell (an HTC P3600, a.k.a. DOPOD 801 or a Cingular 8525 minus the keyboard) took exactly 1 attempt. There is even an interactive web-based pairing tutorial at the Plantronics site.

After initial pairing, the unit takes roughly 3 seconds to power up and about 5 seconds to power down. The two-colour LCD around the call button can display blue and red. Blue indicates the unit is ready and the red lets the owner know battery capacity via flash sequence.

Wear and Comfort:
The 645 could be worn with or without the ear loop. The three silicon ear pieces in different sizes are very comfortable. The ear loop does not exert uncomfortable pressure around the back of the ear. The combination of light weight (less than 1/3 ounce) and the diminutive size of the unit makes it a real joy to wear. After spending the first day getting used to it, I quickly found myself wearing the unit throughout the work day without consciously being aware of its presence. I think that says a lot about the wear and comfort of the unit.

Sound quality and Digital Signal Processing:
This is where the 645 really, really shines! I have been using Plantronics telephone headsets for quite some time and they never cease to amaze me with the sound quality. The 645 produces crisp and clear sound and has no problem picking up my voice in a crowded and loud airport. With the Jabra BT800 (which is equipped with DSP), I had to press the unit against my ear from time to time in a noisy environment just to hear person on the other end of the line. With the 645, however, I have yet found the need to do the same. I guess the DSP is really doing a great job there. The unit is loud when you need it to be - perfect for someone who, according to his wife, is slowly losing his hearing...

Charging System:
This is another outstanding feature common to the Plantronics Discovery series headsets - a charging holder that could be mated with:
• A regular wall charger
• USB charging socket
• 4 charging sockets for a variety of popular cell phone charger such as Motorola, Sony/Ericson, etc.
• A pocket AAA charger

Between charging, the 645 could provide up to 3 hours of talk time.

For someone who spends a lot of time on his cell, the ability to charge the headset without having to either plug it into the wall or a car charger is invaluable. The pocket charger uses a AAA battery and it could extend the talk time to over 9 hours. When the charging holder is mated into the pocket charger, the whole unit assumes the size of a cigar tube and it fits comfortably in the pocket.

For someone who travels a lot, the 645 is simply remarkable. All I have to take with me on the road is the charging holder, pocket charger and the USB charging socket. As I mentioned before, Plantronics has definitely put some thoughts behind the design of the Discovery series, and it exudes that James Bond flair – something that any gadget lovers can certainly appreciate.



Ring Tones and Vibrate:
The unit itself does not vibrate. However, when it is in the charging holder, the holder will vibrate when there is an incoming call. The unit does not have unique built-in ring tones. The 645 does have a series of discrete beeps that alert the user of connection being made, or connection dropped, etc.

Buttons:
The 645 has three buttons. The on/off button doubles as call pickup/hangup button. Along the side of the unit are two buttons for volume control. These buttons are easy to reach and operate.

Pros:
-Superb Sound quality
-Volume
-Noise cancellation
-Pairing
-Easy to operate


Cons:
-None

Recommended:
Yes


Recommended: Yes