OK, luck strikes and the first evening with 50.3 and it rains significantly. This was on street-lamped local roads. Dark outside otherwise.
The rain-sensing is the weirdest one I've ever experienced. First of all, Auto 1 did not do anything, even when the windshield was pretty much full of droplets, so that's out in those conditions.
Auto 2 did function, but in an almost random manner - one wipe here, two wipes there, long random delays in-between, then again one wipe (usually single wipes and then delay), sometimes accumulating significant rain on the windshield, sometimes too much to see ahead safely - I had to override it at times.
It is very distrubing, really, as it stands, having this almost random-seeming mechanism operating the wipers. It clearly recognizes rain, but does so only occasionally. I would say it was worse in dark spots of the road and a little better when turning towards a streetlight, but this correlation remains unclear.
In any case, I would much prefer it to use the wipers with some slowing down/speeding up interval mechanism, like they usually do. This one obviously responds to a yes/no "too much rain on windshield" event - when "yes", it wipes, when "no", it doesn't. There was no continuity, no rhythm, nor any seeming consistency to the wipes.
I think a simple improvement would be to make the rain-sensing have a bit of "memory" and operate the wipers at steady intervals for some time as long as the rain events continue fairly close to one another. That would make for a more pleasant rhythm...