Pros: Very clear, easy pairing

Cons: If you leave it your car on a hot day the little rubber piece that goes in your ear turns to goo

Other Thoughts: To date it the best bluetooth ear piece I've owned, very happy with it.

Pros: Easy pairing. Good audio quality.

Cons: The charging dock simply does not work; it is a horribly designed piece of hardware and I feel bad for the engineer who worked on it. The port where the power cable connects to the dock will not keep the cable connected. The headset will not stay in the dock. Therefore, trying to charge the headset becomes a frustrating game of trying to keep these 3 pieces connected together.

Other Thoughts: Stay away. There are other cheap bluetooth headsets (including other Plantronics models) that will not cause so much pain.

Pros: It is small and light.

Cons: I got this Bluetooth for Christmas after a friend told me about it. I bought the wrong one he had the 644 and not the 640E which is an older model. This Bluetooth was built in 2007 according to Plantonics the maker of the headset. They could not believe that Newegg was still selling it. I got Bluetooth and the ear buds kept falling out they would never stay locked in and the reception was terrible. I would like for Newegg or the Plantonics Company to take this headset off my hands and allow me to get another one with store credit. This is a absolutely terrible Bluetooth and I do not think that Newegg should not continue to see it anymore and if they do so at a considerable discount so it the costumer do not like it they can throw it away. I bought a newer blue tooth and it is working great and it is a Plantonics it is not the company but the design I guess they got better with age.

Other Thoughts: Newegg should take it off their shelves or discount it never sell it at their normal price again.

Pros: Light small no need for ear loop.

Cons: The specs say up to 15 hours talk time. The box says up to 5 hours talk time increasing to 15 with AAA charger. If it's using the charger it's NOT 15 hours. You can't talk 15 hours straight without charging it.

Other Thoughts: The specifications point out 15 hours talk time. They say nothing about needing in between recharges. I'm an upset customer. This wording is very deceptive. When you say 15 hours of talk time it means 15 hours of talk time not. It's not five hours with recharges in between.

Pros: Battery life is great, AAA battery in the headset base recharges headset when docked, further extending battery life.
Sound quality is excellent.

Cons: Gel ear piece does take getting use to; without using the behind ear clip accessory - often feel like I might just drop the headset without even noticing.

Pros: Good sound quality, long battery life, no need for ear loop (at least for my ear), AAA charging deal in addition to normal AC charger.

Cons: Button response time seems slow at times. Gel ear inserts can take some getting used to.

Other Thoughts: I pair this with a BlackBerry Pearl and it has been working great for me. I don't have the thing in my ear all day long and basically just turn it on when I get in the car. So, my battery life comment may be due to lack of use. It stays in my car and only goes in the house about once a month for a recharge. The charging unit works fine for me. I generally have it powered on about 2 hrs a day and talk on it for 10 - 30 minutes of that time.

Pros: Size, weight, in-ear fit, battery life, charging options, easy to operate

Cons: sound quality

Other Thoughts: I paired this up with Sanyo Katana. For a product that gets so many things right, yet the sound quality is sorely disappointing. Even while driving in a car with windows up and radio off, background noise for the person on the other side is intrusive and sound like you're speaking in a tube.

Pros: Comfortable, good battery life, excellent sound quality, versatile charging options

Cons: Earpiece takes some getting used to, earpieces can come off easily

Other Thoughts: My wife had been using this one for a while and convinced me to try it in place of my Motorola 700 and I'm glad I did, it's superior in every way.

Pros: The only plus I can give this product is the fact that it is very versatile when fitting the ear. It has three gel inserts s it can form-fit any ear, and it is very comfortable.

Cons: This unit has the absolute worst background noise out of any headset I have used. It crackled and popped half the time I used it, and I didn't have a single person from whom I did not recieve a complaint when trying to hear my voice. Everyone said the noise was so bad they could't understand what I said half the time. And yes, I was in a quiet environment.

Other Thoughts: When selecting a bluetooth headset in particular, make sure you get the noise canceling capability, this unit does not have it.

Pros: Two ways to charge it, A/C and the pen adapter that uses a AAA battery. The sounds quality is the best I have heard by far. The earpiece is comfortable, but it takes a little getting used to. The instructions are simple and the features are easy to use.

Cons: None so far.

Other Thoughts: I have a Treo 650 from Sprint. Treo owners, this is hea headset for you. I have tried a number of other headsets and this is the first one that has not given me any problems. The call quality is great. The range is good (10-15 ft). The battery life is great, I can usually get through an entire day with it on my ear without charging it. Bottom line, this is the greatest headset I've ever used.