What a sigh of relief. After purchasing the Motorola HS850 and having a horrible experience (see my review), I thought Bluetooth technology was a lost cause. However, based on many reviews I saw right here about the Voyager 510, I decided to try it one more time and bingo, just what I was looking for. So first the negatives for the skeptics like myself:1. The 510 is bulkier than the Motorola HS850 and does not fold up to easily fit in your pocket. I am afraid that I will brake it at times, but it has held up to mild abuse in my pocket.2. It is difficult at times to get on your ear. It is very flexible, which makes for added comfort, but makes it difficult to position on your ear initially.3. The power button is very difficult to use when the headset is on your ear. This is a huge drawback, especially since it is difficult to get on your ear. This is such a pain that I dropped my rating from a 5 star to 4 star. There has been a few times that I forgot to turn the device on before placing it on my ear and I have to take it off to turn it on because the power button is difficult to find and push.4. The device is not too sexy, but I could care less because I was looking for utility not a piece of jewelry. For those of you who do care, it doesn't look as good as the HS850. However, a piece of advice, you don't need to put the sponge over the mic. It looks much better if you just install the ear piece but keep the mic bare.As you can tell by my 4 stars, the positives far outweigh the negatives:1. It works! I can hear everyone clearly and they can hear me, even if I am driving. I haven't tried it in the airport yet, but it has worked superbly in all the other environments in which I daily encounter noise including walking around in the city. This is totally opposite my experience with the HS850.2. It was relatively easy to program to my phone.3. Although heavier and bulkier than the HS850, it is much more comfortable on my ear and stays in place as I walk. The HS850 tended to dangle and not stay in place.4. It is easy to answer and hang-up a call with just a press of the button on the side of the headset.5. Great battery life that last longer than the talk time on my phone.6. 3 different ear pieces that are each shaped differently are included, so you can get the right fit for you. I found one that fit my ear great and I can hear crystal clear with it.7. And let me stress again that I have not had anyone complain that they could not hear me and I can hear others as if I have a wired headset. This headset is truly great if you are looking for a device that works with a Blackberry.And that is the word of D Critique!