Its worth it if you have other mods like I/E/H, reason being is that those mods change the engine set-up ever so slightly and the VAFC will tune it in IF you get on a dyno and have it done properly. Using your ass will not get all the setting "tuned" right and could hurt your motor.

Over all the VAFC is a worthy mod but if you plan on using the car for HPDEs or AutoXs then some classes might not let you use it.

If you do get it, keep it out of sight it has alot of bling factor and might get your car stolen faster.