Excellent cars if you want horse power and performance. But they are expensive and you should buy. The automatic ones are not that great. 

I have a regular WRX(2018) and considered the STI. 
The current gen STI is a great car. A lot of performance for the money and highly modifiable. Great toy/track car.  It is also great car for someone who likes to do their own maintenance and repairs.
 However, it is a terrible daily driver: rough, unrefined, difficult to drive smoothly. It has a lot of HP but it’s all in the upper power band, so around town you never use it. 
Older gen STIs can be fantastic hobby cars. However the usual caveats about buying a used sports car apply.  As much as I love the look of the old bug-eye WRX, I would never want to depend on one to get to work.