Neemobeer, I checked the performance of "Iobits" defragger against windows optimization and defragger tool.
Windows won easily. At 3% fragmented, it only took 8 minutes to finish.
Iobits defragger appeared (and I suspect) to keep relocating files multiple times which I believe made it run longer.
So I removed it from my laptop and will use windows defragger from now on.