Good post. I was thinking about the Supra as a choice to move to before the GR86 was announced; but it was quite a bit more expensive, and, at the time, automatic only, so I ruled it out. Reading your experience reinforces the fact that it might not have been the car for me anyway.
People seem to forget that the Mk4 Supra, the one everyone raves about, wasn't a sports car either. It was a 1600kg, fairly large, fairly heavy, largely sold in automatic, GT car. The GR Supra, despite its BMW DNA, is a very apt successor to that car.
Unfortunately, having run the GR Supra owners club now for getting on 2 years, I've seen way too many people buy the car thinking its a pure sports car, probably because their previous car experience has been Golf R/GTR/M140i or similar. Yes, compared to those cars, the Supra is a sports car. But people who own cars like that will almost always turn their noses up at an MX5, Porsche Cayman or GR86. Proper sports cars don't have automatic gearboxes and turbocharged engines, in my opinion. Supercars do, posers cars do. Sports cars, to the owners of the aforementioned cars, are slow, "boring" cars. They just don't understand how a slower car can be fun.
I have lost count of the amount of conversations I've read, taken part in, or heard that have floated around the topic of power, 100-200 times and dyno figures. When those are the topics of conversation, its quite clear the car in question is not a sports car.