The STI is still one of the best performance values out there and like every other stock vehicle it needs tuning and parts (like more intercooler) to do anything past autocross.
Regarding snow, if you don't think AWD/4x4 helps you in the snow when used properly with the correct tires you've just never driven in bad weather. I've driven everything from 3500 ram diesels to rwd sports cars in snow. FWD is fine right up until there's not dry asphalt underneath your drive wheels. This frequently happens at the top of driveways sloped downhill towards a house because snowplows drop salt on the main road and during the day some of the pack will melt and run down the top of the driveway before freezing creating a nice lip of hard ice that over a few days and weeks of heavy snowfall also turn into a inches thick ledge. When you drive up it, if you can't get enough momentum before the end of the driveway, your FWD car just spins. I would frequently have to back out FWD cars and RWD cars depending on the conditions that winter and how the ice formed on the driveway because I sure as fuck wasn't taking an ice pick to 50 square feet of 3 inch thick compressed ice. That's to say nothing of gravel or dirt roads with ruts that fill with black ice. Or say, when 80% of a road is covered in a 2 foot thick tree trunk and you don't have a chainsaw so you try and you try and cut through snowpack with glazing on the side of the road so the only way to get two drive wheels with traction so as not to just burn one hole in the slush and ice into pure water is to have them both on one side of the car.
In short, if you think 4 wheel drive doesn't help you in the snow you've clearly only driven in dustings or only read about it on the internet.
I mean fuck, sometimes it's as simple as retard in front of you stops and you lose all momentum and you need every iota of traction to get moving again on a hill and one slipping drive wheel means you slip on the other wheel because your fwd car doesn't have a locking or LSD and bam back into the car behind you. I've witnessed that countless times because idiots don't understand conserving momentum in their rental FWD shitboxes instead of adhering to a stop sign with no one coming four miles around.