I'm guilty of not reading the entire thread. I've only seen one of these issues - the smeary driver side wiper. Passenger side has always been fine.
I fixed the wiper issue (I think pip mentioned this) by:
Taking the wiper blade off (takes 1 second) and examining the blade, there was a small flat spot. Bending (gently!) the aeroblade got rid of the flatspot. Worked OK again for maybe a month.
When it strated playing up again, I bent the blade a little more, and also bent the drivers side arm towards the window ever so slightly as well yo increase the pressure on the screen. That was in winter last year, no problem since.
People in countries that don't have the aeroblades won't get this problem. Aeroblades are cleary art, a triumph of form over function.