That is an excellent review! I totally agree with your final one line conclusion which aptly describes the STi-R:

"The Beltronics STi-R is simply, the ultimate dedicated remote radar detector."

The only thing which you forgot to mention is that the STi-R (now with its latest firmware which features the audio ramp-up fix) features, as other Beltronics products do, a very linear visual-audio ramp-up profile. This is one particular aspect of Beltronics products which I really love.