there is heat soak if there is leak in the heatsheilds. the R2C's were much better IAT wise vs others ive tried, nearly stock unless stopped for a long time. im not here to bash other manuf's short rams so i will leave it at that.
but you buy those short ram kits for the response, not power gain imho. the time it takes for the throttle to respond is much shorter and a lot freer mid-band. stock box bogs worse when outside rev range. i use to be able to easily chirp 3rd but with stock box HPS+K&N = harder... actually havent been able to yet.