I always sit down.
Provided the loo is clean of course, if I'm at some stinking loo in the pub or some such then obviously I'd invoke my manly right to stand.
Don't really understand why anyone wants to stand up to piss.
Main issues are:
• splashback and splatter – go for a piss in a urinal in light coloured chinos, examine chinos afterwards and report back with your findings. 😕
• aim – I'd rather not accidentally piss on my own loo seat as I'm the one that has to clean it. Yes it's not a difficult target but I'm sure we've all experienced the unexpected perpendicular pee, the surprise side stream or the unplanned dribble.
• shaking – so you basically just shake piss all over yourself. Nice. I'll use a bit of paper ta.
• comfort – I'd rather sit down and take the chance to check my email.
😀
What possible benefit is there in standing?