Rocketbelt is a bait item. I used to run it, until I saw how much stronger I was without it. You don't need the hp when you 1 shot the whole ennemy team 1v5. As for the gap closer you don't really need it when you know how to properly use your e. I got over +1000 lp in like 2 weeks with it (76% wr). 100% lane stomping. But hey keep running rocketbelt all you want. Thanks to people like you, riot is not nerfing ken <3