Issues with fast freehub wear:
The freehub has about 1 mm play when it’s new.
I had these hubs on several bikes since I was a teen boy, I have been using these freehubs until failure, and the freehubs lastest about 1 season before they failed, so I couldn’t pedal, but now as I am an adult, I wear them in few days so the play will be significant, which reduces shifting performance, and I can move the freehub in all direction with knocking sound, I Won’t would not take the chance of being many tens of kilometers away from my home, and needing to call a taxi, So I had to swap the freehub,
any play in the freehub will cause wear in the cassette and chain, I think I should upgrade the hubs.
With proper hubs with proper freehubs you will get zero play no with a lot of use and abuse and crashing, for example, Hope pro 4, It has been problem free, and has not shown any signs of wear after a whole year of use.
Service interval king:
No proper seals, causing contaminants like water, cat hair, and to come inside the hub, so if riding in the winter you would have to service them every week to 2 weeks intervals.
To service the freehub you need a special tool, which is difficult to get, or you have to make one your self, This is not acceptable.
RJ The Bike Guy made a great video showing you how to service Shimano hubs:
Annoying low engagement:
The freehub has a horrible engagement, so you have a big dead zone before you actuate freehub, making technical claims harder.
because of the outdated design, and reliability issues and the extreme service intervals, I can’t recommend these hubs, these hubs are a nightmare.
I recommend getting Hubs with sealed cartridge bearings, and more bearings, and an easier more modern design, Hope and Industry nine are a perfect example of this, are more on that list of course.