What really surprised me was the positive controller: Bigger and heavier than my GH2 Explorer (meant positively, acts of "real"), no cables to trip ... The buttons and strum bar are perfect when it comes to stop behavior, and significantly quieter than the old controller. Plus, there's an extra key for "Star Power", which is conveniently located under the ball of the thumb - no jerking when verzeifelten attempt during a complicated passage star power to activate. May be that it gave earlier, I only have the GH2 and the GH5 Controller - but at least all the people in my situation I would recommend buying the pack for a reasonable price.
The controller also makes GH3 and Rock Band for a better game, if one has previously put on the old hardware.