The version used in the video in fact is actually a previous version that had a bug where the CPU usage would max out to 100% sporadically. That's been fixed in his latest version, 1.43 I believe.. however the method he's used to establish root in 4.3 is not inherently stable. Nothing against him - I understand it's a work in progress and for now it may be the only hack to get root access on stock 4.3 and if people NEED root right away on 4.3 this should work alright for the time being, but it is not bug free nor "perfect" yet.