IOBit's Advanced System Care.
It's like a dirty word in these forums. Frankly we never recommend IOBit software and you will see if you search the forums why. Too many users end up here reporting problems after using it or any registry cleaners or System Optimizer tools.
Your choice here. You seem happy with the free version so why upgrade?
I have to ask though. What problems do you have with viewing videos on YouTube? I don't have any problems and don't use ASC at all, nor anything of its kind. What does 300% faster mean? The videos play 3 x faster? I prefer my videos to play at normal speed.