Well, the Impreza feels like a huge downgrade in all aspects when compared to the Legacy, much more than a mere $3000 price difference would have you believe. While the new suspension is a bit better than what you
used to get on a stock Impreza, it's still taller and less sophisticated than the Legacy suspension, and therefore leans more in corners and rides rougher. The base Impreza also stepped backwards to steel wheels and rear drum brakes.
The interior sucks, too. It was ugly and uncomfortable. I felt kinda silly while sitting in it.
The Legacy feels a lot classier, and still offers better performance in just about every aspect. The exterior seems more refined, with minimal wheel gap, a lower stance, nice 17" wheels and better tires, and little extras like moonroof, etc. The interior is much more comfortable and attractive. The suspension rides more comfortably, yet is more confident in corners, with less body-roll. The 5MT is also buttery-smooth. I think the only con that I found was in the fact that 2.5 liters don't go quite as far when coupled with the slightly heavier chassis. . . but it seems to be geared well, so it wasn't a big deal.
I'll probably go for a Legacy next, if I decide to get rid of the Impreza. And I just might. . . I'm kinda tired of having something that everyone else expects to be a WRX.
Oh, and I sat in the white '08 STi that they have sitting in the showroom. . . there's a nice, sporty interior that's a lot roomier than it looks from the outside! The seats are apparently still made for
large people, unfortunately.