I have an '02 WRX, so maybe my ownership experience can give you some insight.
First of all, expect to have to replace your engine at some point. The EJ205 has a known problem with spinning crankshaft bearings, the failure comes down to not having enough oil capacity for how much power is produced from those 2.0 liters. STis and other 2.5L subies also have this problem, but they have a superior oil pan design that helps mask some of the other minor oiling issues in the EJ engine family.
Moving on from the engine, early transmissions have a bad reputation for being made from "glass". I've autocrossed my car for years (no real drag racing to speak of) and the trans is trouble free. The SPT short shift kit really gives a great feel to the shift action. The lack of a front LSD in non-STis will hurt high-power and offroad performance.
The stock suspension and brakes are adequate and the suspension has quite a bit of travel at the stock height (8 inches total travel in the rear), but the H6 rear brake upgrade is a low investment, high reward upgrade if your car ever needs a brake job. Wheel bearings will wear more quickly if rallied.
The bodies and interior are solid and durable, but there was no AUX input in the stereo until 2007. The paint is pitifully thin on all WRXs and 02-03 front wheel well skirts break every ski season and are a pretty poor design to begin with.
My advice with WRXs and any other car is to save your money, be patient and find the nicest, most stock, lowest mileage, best documented one owner car you can find. It will save you innumerable headaches down the road. If you do buy one, the first mod should be a catless uppipe. If the pre-turbo cat fails, it will take your turbo with it.
Edited by carfreak85, 08 February 2014 - 07:54 PM.