Which property would you take?

The 600 sq.m plots usually look like this ..

Not where the black line is, but the small red ones.

Correct
Just download the picture and zoom in

The 600er plots usually look like this ..

Therefore, I find the 655 very good.

I am into retention basins. As far as the properties in the west on Moosirgendwasstrasse. These retention basins provide a property with a nice boundary to others

My favorites would be the 655 or 635 with the road in the north. The Moosbroksweg seems to me to be the (relatively) most heavily trafficked road here, and with its tree lining it would also block evening sun. I didn’t feel like searching through the 2,236 development plans of the district, but there could be decisive nastiness in there regarding street trees / driveway locations or possibly ridge directions. And of course building envelope locations would be interesting. The aerial image offers hope that it is flat or very evenly slightly sloped. Otherwise, such fun things as valley-/ridge-side eave height requirements might also come into play.

655 or 635