i have an sti cbe and a sri and it is performing noticeably better, but from what i have heard your ecu cannot be open source tuned. you are going to have to get a piggyback ecu. But do that after you get all the mods on, that way you can make sure everything is tuned correctly and you are getting the most power out of it. also, lightweight pulleys and headers are good mods for the rs. honestly, you still won't be getting a lot of power, compared to a wrx. but i love my rs and i know you will too!