well put it this way, people could go on and argue about the difference. but in the end, you wouldn't really feel the difference.
its like this, if ur car for exampe ran at 18 second quarter mile, then it would be real easy to put any mod and get 17 or so the second time u run it. BUT! if ur car has alot of mods and runs at 12 second quarter mile, then i wouldn't be as easy to loose another second. get it? so basically, tha faster u go, the harder it is to go faster.


so. on a lighter level if people can't really feel the diff. (perfomance wise) between RSI and CAI except for sound, then i would be even harder to feel the diff between if ur cai is restricted. right?! cuz the by pass valves obviously sits between the pipe, therefore restricting it. so now. one could argue about spending more for CAI and plus the by pass valve for almost the same performance quality and lesser value of the RSI.

but to answer ur question, yes! it still beats the RSI by only so much that u can't really rely on it. especially when driving skills are involved.

i hope that i answered ur question with clarity.