I tried (and returned) 5 different headsets and was about ready to give up on Bluetooth altogether and go wired when I came across the 510. Three things clenched the deal for me:1) on every forum I looked, the user comments were overwhelmingly positive. In fact, I have yet to see another headset with such consistently positive user reviews. So far, this headset has performed well beyond my expectations in terms of sound quality, features, and reliability of operation.2) This headset supports multipoint technology. For the price, that's hard to beat. I use it with a Motorola PC850 to connect to my laptop. Since -unlike my minutes- my data plan is unlimited, and I found out that Skype works remarkably well over a mobile broadband connection (EVDO), I can use it to call for free while on the road if I happen to have my laptop up and running. Since I can use the same headset with the laptop and Skype, it's extremely convenient.3) For such a highly rated headset, the price is unbeatable.Unlike the other headsets I have tried (some more expensive), this one sounds excellent on both ends of the conversation (I tested it myself before subjecting someone else to it), no static or crackling noises. Sound quality on my Moto Q is excellent all around. I also like the fact that it's easy to switch to the left ear, since I hear better out of that side. The headset is very comfortable, even though I wear eyeglasses.On the down side, operation seems a bit less than intuitive, especially switching back and forth between laptop and cell, but it's probably just a matter of getting used to it.The volume and power buttons are indeed a bit on the small side, but after some time getting used to them, I can now find them and use them effortlessly (they have registration marks - if you rest your index on the 'valley' formed by the two volume buttons, your index will naturally rest on the power/mute button. After you realize this, it becomes second nature).Bottom line, you'd be hard-pressed to find better in this price range, maybe even at twice the price.