well, for my 4g ipod, i have the itrip, mostly for the reason of the no-wire intervface with the ipod, it just sits on top in the headphone and remote ports. Personally, i think the ipod mini itrip fits even more seamlessly and looks better. in my experience, it has good range - through from upstairs down to the basement. Also, depending on where you will use it, there are many that integrate a car charger for it as well, and also, like the tunecastII, it has a digital tuner with a small lcd to show the station at all times. also, most other fm transmitters require batteries of their own, except the itrip and aforementioned car charger/transmitter ones. I highly reccommend checking out the CNET guide to ipod accessories for a little more details on a wider range of options