i got the FR-S, and probably if the BRZ was more available i would of purchased it.
i had never owned a subie , but i have had good luck with Toyota. in the end, its brand over goodies... hard to say but after driving my new one for 120miles, i have no regrets - there is always something better but the FRS by itself is nice.
the stereo isnt that bad actually, and i did drive the BRZ-Base before and i didnt like the radio on that one - it was actually weaker and when i checked it was something like 190W instead of the scion 330W.... so, tit-for-tat but cant go wrong with either