You Don't know Me!
Si handles more like the brz??? What??? FF vs FR are totally different.The Si handles more like a BRZ than a WRX, that's the main reason why cross shopping the Si and WRX is like picking between cereal and steak... You're usually in the mood for only one. Your first test drives should solve that one. Plus the WRX is due for a massive redesign so I wouldn't go for the old model. And I'm not a fan of the boxer engine and Subaru's typically high road noise cabins.
Either way, either car is good.