Geez. That's absolute rubbish. Haven't heard to much bad about them to be honest but now, wow.

Good on fuel, has decent power and torque for its engine capacity.

Generally people would go headers (PLM seems to be popular), catback with high flow cat (Invidia is excellent but pricey), intake (custom made or something like Injen), Bigger throttle body (J35 also seem popular) different VCT cam, Hondata tune. All that does come at a price though.

I'd personally just put an exhaust to get a nice sound. VTEC engagement is quite high on the K24 engines (above or roughly at 6000 rpm).