Last week I did it. I upgraded from a 2004 Scion XB and went to 2006 WRX. Holy wow these cars are fast. It's all stock and i'll more than likely keep it this way. My first thought when I went to test drive it was the same thought I had when I bought a 1997 YZF600R back in 2000. I thought, "Geez, i'm gonna kill myself in this thing". The speed is unbelievable, the handling is amazing and I love the AWD. I drove the scion a few days after I purchased the WRX and I thought i'd never get to 40 mph. One thing i am going to miss about the scion is the great gas mileage.
I love this site and so far people seem pretty cool in the forums.