I have been using the Supertooth II for only 48 hours but I have some initial comments. I have a daily driver (A BMW) with full Bluetooth capability built in and I wanted to get a device that I could use in my (weekend) fun cars that would allow my Motorola Razr to operate hands free. The integrated system in the BMW is fantastic and has spoiled me but I am still delighted that I can move from car to car with one phone and hence one telephone number and still have handsfree operation.I looked at other devices and they were divided into two catagories:1) Really nicely designed integrated systems (like Parrot's offerings in the market, for example)that had display screens and offered a full range of control similar to the integarted systems.2) Clip on devices that had limited capabilities but could be moved easily from car to car.The devices in category 1 had two disadvantages: (1)They required a dedicated installation to integrate the audio system for speakers and muting of the radio. (2) They could not be moved from car to car.The devices in category 2 seemed to offer weird plug in the cigarette ligher thingies that were just plain ugly and clumsy or they offered visor clip-on boxes but bad sound quality and cheap looking construction.The Supertooth falls into category 2 but seems to be very well made unlike the others brands I looked at. It looks less obtrusive in the cars than the lighter thingies or the cheap plastic boxes.So...The Good:The magnetic clip mounting is brilliant. I can leave the visor clips in place and very easily move the unit from vehicle to vehicle. I even guess that it would be possible to carefully install a metal plate under a part of the hard headliner or visor so that the Supertooth would magically clip on when needed and not even require the visor clip. I have not done this but have been thinking about it.Set-up is childs play. It took me about 90 seconds to register and connect to the device.The controls are simple and intuitive. I am delighted with anything that has a rotary knob to control the volume instead of push buttons. Sometimes old fashioned human interfaces work really well.Although I cannot swear to it, it has been reported that the battery life is outstanding. That is pretty important to me as I may forget to transfer the car charging cord with me when I move from one car to the next.The Bad:With the Razr, I must press the pick-up button every time I need to re-establish the bluetooth link. I am spoiled by the fact that the BMW system just knows when I am within range and automatically connects.An particularly evil (maybe it's just the Razr) annoyance is that when I do press the button to establish the link, the phone automatically goes into voice recoginition mode. This is really agravating as I must give it some command to make it shut up and half the time it winds up dialing a number when I don't want it to.There is no caller ID display. I cannot screen calls unless I dig the handset out of my pockets and check the CID. I would have liked to have this feature even if it added to the price.The Could Be Better:Sound quality is OK from the speaker, not spectacular. The microphone, as long as the unit is mounted on the visor, seems to provide clear sound to the caller.What good is the call reject button without a CID readout? I just don't understand why it is there.Why can't the unit sense when it is disconnected from the BT link and just power down automatically? I get that it can't power up by itself because that would require it to be partially on all the time, but why not have it power down automatically?One last tip: I discovered that I can leave the unit powered down (with the microphone folded) and when I receive a call, I can flip the mic down and press the pick-up button and it will connect. It takes some finesse to time it just right (it takes a few seconds for the BT link to be established) but it seems to work pretty well.I hope this information is of some value to you.