My rule of thumb: If there's anything concerning a kernel exploit on firmwares above 5.3.2 (or even 5.4.0), it's fake. I've pretty much lost hope for the Wii U to be hacked on 5.5.1. If Hykem's exploit wasn't fake, the raids have pretty much made anyone who can exploit it too scared to do so. This is pretty much the PS3 all over again in that there's a max firmware that has an IOSU exploit, and if you go over that, you can pretty much forget about hacking it.