I have a PS3 with 2 of these SISAXIS controllers and they are great, the motion sensitive play is good, and the lightness of it is nice , but i've only just realized that sony have taken away the vibrations, i big miss, sony said if there have vbrations it would interfere with the sisaxis motion sensing, but the wii remote has vibrations and is motion sensitive.
soooooo... sony got working and have come up with something better, DUALSHOCK 3. It has the Sixaxis motion sensing, and is still wireless, connected via bluetooth, but with vibrations.
the DUALSHOCK 3 will be available spring 2008, if you want another sixaxis controller, you are better off waiting for DUALSHOCK 3...