2009 WRX is a great car. Best bang for the buck when compared to the STI. Also the STI has a stiffer spring setup than the WRX so you may want to take both out for a test drive to compare.
I owned a 2002 WRX up until recently (as per my signature). I bought it brand new and traded it with about 97,000 miles on it. Overall very reliable car. Outside of normal maintenance items I did have to get the water pump changed and something went wacky with the anti-lock brakes where they became "hyper-active" and would basically kick in even on normal stops. I also needed to have a valve cover gasket replaced, 02 sensor went bad around 85k and the dealer needed to fix a fuel leak issue that would occur in the cold weather. This issue really only affected the 2002-2004 cars I believe. Anyway, those issues were fixed and the car ran strong for the entire time I owned it. Mine was a 5-spd and I was still on the original clutch as well. Also the car ran very smooth, very little buzziness to the boxer engine even at high rpms. Very smooth idle as well. That turbo sounded great when it spooled up.
I have heard of random Subies suffering from spun bearing issues from time to time. It's rare but it does happen, you can find examples on YouTube. Also the boxer engine does have a tendency to develop a piston slap noise due to the design of the pistons when the engine is cold. Dealers know about it and basically consider it normal unless the noise is still present when the engine is hot.
Before I bought my G8, I did look at a Legacy 2.5GT Limited. I just couldn't find one around with the manual trans in a color I liked at the time or else I might have bought that instead.
Ed B.