I'm German and I fish the river Isar as well as many Alpine streams. In 2024 I was faced with four issues related to my wading boots:

1 Purpose) due to climate change many of our Alpine rivers do show a fair amount of algae growth in summer which lasts well into autumn making wading in those streams very slippery not only on bigger rocks but also on gravel. A rubber sole with cleats does not provide the necessary traction when wading. I have never considered boots with felt soles as they don't last very long.
2 Comfort) I apparently have sensitive nail beds which get frequently injured when climbing or walking downhill with the nails hitting the very hard upper shell of my current wading boots from a major US brand. My dermatologists is looking at me in disbelief "don't you fly fishers wear decent comfortable boots?"
3 Quality) I've bought the flagship shoes of a major US brand which got taken over by an investor 2 years ago. They have disintegrated after just two seasons. The cleats either fall off (even when fixed with screw glue) or they start to rust and cannot be removed and replaced when worn out.
4 Social Aspect) I'm just above 50 and I fish with a bunch of young guys. Most often they're ready waiting for me while I'm fixing my gear or bind the laces of my wading boots. This of course results in nice comments such as "Not ready yet, grandpa?" They all wear boots with a BOA system which they got from Rudi Heger....

So on a sunny Friday afternoon, I hopped into my car, drove to Siegsdorf bumped into Ralph and handed him the 4 points above. He smiled back at me uttering the word "Darkhorse". While I initially thought that he has seen too many StarWars movies, I quickly realised that the Darkhorse is the comfortable universal wading boot in the Worker's BOA wading boot line up.

1 Purpose) the first steps with a felt sole made it very clear, the traction these soles provide is on another level compared to rubber soles with cleats. If this is not enough, use the studded felt soles, they even provide greater traction. The increased traction have a practical consequence, I wade more aggressively and I'm able to reach fishing spots in the river. Thus, you will catch more fish with these boots. I will never wear rubber soles again.

Never? Never in the water, there's one downside of felt soles: they are extremely slippery on wet grass.Shortly after changing to my Korkers, I made sudden contact with the forest floor walking over wet grass. But there's a fix for this, change to the rubber sole when walking larger distances. I do carry my rubber soles in the back pocket of my fishing vest and with a little exercise now manage to change them without taking them off.

Last but not least- weight. These wading boots are extremely light when equipped with a felt sole. In my fishing group one of the young guys is wearing the top shoe of another major US brand with cleats that look like tank tracks. He frequently falls behind when we hike to a favourite spot a kilometer away from the parking spot. When he arrives, the best pool is already fished.

2 Comfort) My dermatologist is happy and now convinced that fly fishing is a serious outdoor sport with up to date boots, so am I.
3 Quality) cannot judge it after a single season. The boot however, still looks like coming out of the box after one year. I'd estimate that the felt sole will last between 20 and 40 days on the water which for many of us is between 1-2 seasons.
4 Social Aspect) No-one is calling me grandpa any more in my fishing group. From time to time, I teach the young guys a fishing lesson because I now reach the very same fishing spots the river they do. There's still one guy in the group using boots with laces, he was the last to get ready on the last day of the season. I stood next to him to provide him with mental support telling him that I love the slowness of fly fishing - he got a new pair of Korkers for Christmas........

Conclusion
This is the perfect boot, I will probably not use any other for the rest of my hopefully plenty days on the water to come. This way my best gear buy in 2024. Thanks go out to the team at Rudi Heger guiding me to Korkers Darkhorse