Well, lots of reasons. For one when we had a lot of snow and ice here in St. Louis all of us who called in to work got in big trouble. I'm tired of worrying about that. The Celi is lowered so much that it would start snowplowing if more than 2 inches of snow/ice is on the ground. Not to mention I didn't want to have 2 sets of tires for summer/winter. So I went with an AWD car.
Two is I really love mountain biking, and I could never find a good way to carry the bike with the Celica. Bike racks either don't fit or just look STUPID on it
When I bought the GTS I was totally ignorant about cars and things like that. So I got the triptronic auto transmission. In order to do any more modifications I would have really needed to do a transmission swap before turboing it. It was more economical to buy a new car. Especially one that was already Turbo.
My friends can now ride in the car with me with the back doors and usuable back seats. They hated the Celi's
I'm going to start college again in the Fall for film school and needed to be able to lug around film/video cameras and boxes, and be able to go remote places to film. On my last short film shoot we had to go up a rutted dirt road up a mountain side. The Celi with its low clearance would have been torn to hell.
So all in all I with all that together, I decided to get the STi
I still love the Celica though. Great car, great gas mileage, great top end speed. Reliable as a rock