I had one for a few days and sent it back. Sometimes the calls were as clear as a wireline and other times you could hardly understand the person on the other end. Interesting enough, the caller on the other end said it was perfectly clear while what I was hearing was very unclear. I really think it comes down to your broadband connection. For some it works very well while others I have heard experiences similar to mine.

Like was noted before, you need to keep your computer on continuously if you want to receive calls.