I have received several PMs and Emails regarding the the performance of the STI-r compared to the 9500ci along with the undetectablility.
As I have both units and a Spectre III, I can say without question that both are totally undetectable.
As far as performance, I see no difference. Both offer great range, sensitivity, off axis detection.
Therefore it comes down to:
Choosing the 9500Ci over the STi-R because of its GPS capabilities and the ZR4 shifters or; choosing the STi-R to save a few dollars and doing without the GPS and Shifters.
In my review of both units, they each offer the best in radar detection over any other unit that I have ever tested.
Hope this helps...