Although the V600 is a great piece of technology, it has not been working real well on the Cingular GSM network because of excessive static. I've heard Cingular is not selling the 600 right now because of software defects--supposedly a newer version is coming out that actually works. Anyway, the V400 has basically the same features, a much lower cost, and far less static interference than the 600. Definitely the way to go