This thread is worth reading from someone who has owned a first gen and a Supra. I guess the 2nd gen is even better and maybe the Supra is now more engaging being a manual.
From what I gather the Supra is more a GT car, faster, heavier but more refined. BRZ is lighter, raw and more engaging, but slower.
https://www.ft86club.com/forums/showthread.php?t=137156