Been there, done that - went through 2 of them in 3 years. 3 speed hubs - at least the ones I tried - are low-cost assemblies for low-cost bikes. They're definitely not 'sealed' and in the winter they rust out internally. I also broke the bearings because they're not designed for an adult who sometimes stands on the pedals to get up a hill or through the mush.

I hope those expensive Alfines are tougher, or people buying them for winter use are going to be disappointed.