Knowing whats on it, configuring it the way you like, selecting a different distro you prefer, certainty that if you needed to you actually could deviate from t

Knowing whats on it, configuring it the way you like, selecting a different distro you prefer, certainty that if you needed to you actually could deviate from the OEM install... There are plenty of good reasons to load your own OS on your own hardware, that aren't purely for the exercise.