Here's my two cents...
The WRX and STI are basically two different cars. Pretty much has two completely different motors. The WRX isn't just a "watered down" version of an STI it's basically a different car
The Ralliart on the other hand has the 4B11T motor that's in the Evo X.
Breakdown: The Ralliart has the same engine as the Evo X, Same transmission that's in the Evo X MR and SE, and same AWD system as the Evo IX.
However, the Ralliart has a single scroll turbo and a smaller intercooler (De-tuned). And the Evo X has a twin-scroll turbo, larger intercooler, and tuned up to match. Basically a truly "watered down" version of the Evo.
Both scoobies and mitsu's will always be beasts on and off the road. Both are badass cars that will be talked about forever. You can't go wrong with either of them...
BUT, if you get a Ralliart you can get a used Evo X turbo, Evo X intercooler, Evo X bov, and get some uicp/licp, boost pill, intake, exhaust, and tune and you'll be rapping rex's and sti's all day errrrrrrrrday
Fin