After some reconstruction and 6 Baskets added this course has a lot to offer with its variety, doglegs/mandos, trees and water hazards.
6 holes have water in play and make it really thrilling sometimes and quite unique. The layout has become even better and fits perfect in the park yet some holes require a quick walk.
The flow however is still good.
The park seems to be well maintained every time i got there.
Basket #18 is close to #1 and a kiosk is in between.

Still the biggest problem with this course are the pedestrians and park goers. Many people use this park for recreation and sit down on the fairway (on warm sunny days), making it unable to play all holes or passing by/crossing the fairway, making you wait some time. There are no real tees and some holes can be a bit muddy.
Many holes have stinging-nettles off the fairway.
Holes #6 and #7 are a bit unfair due to the trees which can make your disc bounce of easily into the water.

There are many things to do at the Revierpark Wischlingen lika a brine bath, Mini-Golf pedestrian walks and some playgrounds. There is a ropes-course as well which sometimes proceeds right above some fairways.
The reconstruction was a huge improvement to this course. Almost everything enhanced yet the big problem with the high frequentation stays.
Nevertheless its a pretty nice course now.

Maybe you should bring a brailer or bathing-trunks. You might also rent a boat there to get your lost discs. ; -)