uhh while i enjoy the dig at the iPhone and Luke Wilson, what you said was inaccurate: GSM allows simulatenous voice/data while CDMA does not. Its about the network infastructure, not about the device.
To stay on topic, I could not cancel my home connection. no way jose, I download waaay to much stuff, and rely on wifi for other devices. I do tether on occassion when the home connection goes down, or when the bandwidth is being hogged by my PC gamer brother, and so tethering it is a nice convenience to have. However, it won't replace a home connection for me, and for the alot of people.