Just a quick feedback after 3 sessions:
KL-3: No... just no... bad flight, bad durability... I'd easily prefer hybrid shuttles to these. Directly donated the rest of the tube to the club for kids' practise.
KL-Bronze: Better, but still not in a range that is significantly better than hybrids you get at the same price locally. Flight is okay, durability was mixed. Again, direct donation to the club kids.
HKO-4: nice shuttles overall. Stable flight and consistent durability. They match the overall performance of the Forza S-6000 imo.
HKO-2: Great shuttles. Playing those after testing the others makes you realise why high class natural feather shuttles are so much fun to play. Those are clearly comparable to AS30 imo. If I was seriously going to order a bigger bulk of any of these shuttles, the HKO-2 would be my first choice. Looking at the prices, it's around 21 USD before shipping and import tax, so I guess I would end up at around 23 EUR when ordered in reasonable amounts. Not the super steal that we might have hoped for, but still a good bang for the buck value imo. So we will think about ordering more of those for the club and maybe add some tubes of HKO-3 to test.
Overall summary of this test: You get what you pay for.
I have tested the new Victor NCS shuttles in parallel and frankly, those were the overall winners for us. Flight and hitting feel on the level of the HKO-4 and a consistent durability of 2-4 games. ~19 EUR ordered locally. Unbeatable.
In my very personal opinion, those synthetic shuttles are the future for casual play, club practise and lower level tournaments. If I imagine the current NCS with added fine tuning and further developments in material, they will make natural shuttles obsolete pretty quickly.