I second that, not yet from experience, but I've heard many say the same. For what you get out of it, it's real cheap.

Best mod is the supercharger, but it'll run you something like $2700 for it, plus labor. It'll boost your stock 215hp up by another 50hp.

Some swear by the K&N air filter, which runs about $40. I'm still not convinced so I'm on the fence about trying that out.

I think as far as fuel efficiency goes, the best thing you can go is keep up with basic maintenance and not use your power mode. I use my power mode more than I don't though because I notice a real difference and it's more fun with it engaged. I can definitely tell I get to visit the gas station more too though.