I've done a lot of testing with my stock intake system and with an SRI.

I installed a K&N drop-in filter with the resonator deleted, then attached a short length of pipe to the air box. It definitely works better than an SRI, but I don't know about a CAI. It isn't blingy but it's cheap, and it sounds good without being annoying.

By the way, the piping for an AEM is smaller in diameter than stock, until you get back to the resonator. I'm not kidding.