Lenovo G50-70 or Lenovo Z50?

According to lenovo, the G series is intended to be the cheapie model for people who don't need full power laptops for demanding games and multimedia. The Z series is intended for multimedia and some gaming (but not the super hardcore stuff), and is therefore more expensive. I have a hard time distinguishing them otherwise, but one assumes that the Z series model is the lower end of the Z line and the G series model is the upper end of the G line. The speakers and the Wi-Fi on the Z series tend to be better, and the power consumption of the G series tends to be leaner. I'd go to a retail outlet to try out the keyboards and the overall feel of representative units (if possible: all G models and all Z models should have the same feel) and decide that way if the premium on the Z model is worth it.