The 2013 Subaru WRX and STI are reasonably practical, considering their performance missions, and while they're not particularly roomy, they're just as usable as most compact sedans and hatchbacks.
They're technically five-seaters, though larger adults will find reason to complain when there are three across in back. Standard sport-bolstered seats in either WRX or STI models are comfortable and supportive, but the optional Alcantara-surfaced Recaros available in the STI are a great upgrade, enhancing the cabin with a racier look and more comfort, too. Do keep in mind that these racing-style seats come with a fixed headrest that some testers have found uncomfortable.
The hatchback's extra cargo space is handy for luggage, although versatility is a bit lacking compared to other hatches this size as the rear seatbacks don't quite fold to a flat floor; likewise in sedans, which have a large trunk, the cargo floor includes a sloped, uneven floor that can make stowing large boxes or suitcases into more of a chore.
Although the rest of the Impreza lineup, on which the WRX and STI are based, got a substantial upgrade to materials, fit, and finish, these two performance models are no longer in pace, and compared to many of today's small cars (many with a lower price), the cabin trims don't stand up so well. Upgraded seats and some trim upgrades in either of these models to earn premium accommodations in some respect, but they're nowhere close to luxury-grade.
Considering they're performance models--with crisp handling response--both the WRX and STI handle bumps, potholes, and coarse surfaces with aplomb. We've noted some engine rumble and wind noise from the side mirrors, but otherwise it's very quiet in the cabin. The STI's considerably louder (lower and pulsating) exhaust note isn't obtrusive while cruising, though you'll notice it when accelerating.