Usually I do sit...that toilet water is COLD!
1.) When I sit, the water IS cold on a 'builder's' toilet (the cheap, smaller kind generally installed by home-builders in modern housing). I have tall boys installed in the bathrooms of my home so that there's no contact with the bowl water. I find I get a pleasurable 'completely voided' ache, sometimes with contractions after a complete emptying of my bladder--I've heard other men joke about this, referring to it as 'the pee shivers'. If I have to use a public toilet, I use the stall, piss as much as possible first, then hold my cock and balls up and out of the way as much as possible if I have to shit. I don't like the sanitary conditions in public toilets, and don't like having my cock and balls touch toilet water. It's not just so much that the water's cold, it's probably less clean than in my own toilets (yes, I clean my own at home, too...). Splashdown is for space-capsule recovery, not my cock and balls...
2.) Also, I am a two-streamer: when I let loose with my piss stream, there seems to always be two streams for a while--one from the top, the other from the bottom of my piss slit. I think it has something to do with the fact that my meatus (piss slit) really is longitudinally long from top to bottom, and there may be some coherence in the midsection of the meatus during the first outflow.
3.) I like privacy. It's such a physical pleasure to void (both piss and shit), that I want to be completely alone and able to concentrate on the physical sensation. I remember hearing men joke 'there's nothing like a good shit'--and it's true, for me. I guess I am more viscerally able to take pleasure in this than men who just 'do their business' (probably the result of overzealous toilet-training by females).
I was raised by a single, widowed dad: my mom died two weeks after I was born in an accident.
4.) I don't like looky-looky trolls at urinals that you occasionally run into in public bathrooms. For me, that always interferes with 'letdown' or a full void.
TMI, or what?