IT could be a scam, and it could not be a scam. If you're getting an intake for your car, get it well planned, match it with other bolt-ons. Avoid lego building.

I bought an AEM V2 for my integra a couple years back and yes it surprisingly improved the torque and throttle response. It was too loud too that it sounded like I also have an aftermarket exhaust system.

1-2 hp gain, you can HARDLY feel it regardless of how hard you drive your car... 5 hp advertisement is a scam, too, however Injen claimed an inicrease of around that much on various cars. K&N also claimed to gain ~7-12 hp gain on cars already making 250+ hp, and those 3.5 - 5.0L...

You're not going to see or feel the gain in power with just an intake system...