Quote Originally Posted by CollegeHumor
STANDING
PROS: Easier access to affected area, immediate gratification of seeing what you made in the bowl

CONS: Risk of getting poo on the floor that wasn’t quite out when you were still sitting, possible strained hamstring

Sitters will argue that when you stand up, the poo “mushes together” between your cheeks, but I can assure you that is not the case.

SITTING
PROS: More relaxing, very little chance of poo ending up on the floor

CONS: Small risk of accidentally misjudging and sticking your hand in the water, harder to cover all surface area.

I believe this guy has it right, and that whichever side you're on, the other side is weird. Article.