All suspension aside,
2.5 N/A is quite good for rallycross. You get to be in a very low class, and you get to stay somewhat competitive. The differences with 4EAT and MT are not as apparent in rallyx vs autox because you can't lay down the power as hard in rallyx. That, and left-foot breaking is just easier when you don't have a clutch to worry about!
Plus a lot of people actually prefer N/A over the Turbo Subarus because of the even power delivery. It provides a predictable exit.