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.
The deore h bs have rubber seals, instead of steel covers, buttjey are compatible with the m475 hubs Shimano Bl-M525 L.H.Lid Unit – Y8S49801
To service these freehand, 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 climbs harder.
because of the outdated design, and reliability issues and the extreme service intervals, even if you swap to the seals for deore, as the freehubs wear out so fast, that it’s pointless to fix it. I can’t recommend these hubs, these hubs are a nightmare.
There are far better options out there, I recommend getting Hubs with sealed cartridge bearings, and more bearings, and an easier more modern design, Hope and Industry nine, Chris king, are a perfect example of this, are more on that list of course.