This is an early review as only managed to get the axle installed recently and so far so good. Despite the pain associated with whole process of getting my rear wheel functioning properly again, I'm giving a rating of four stars. This is only because Matt in the customer service department at Hayes was there to quickly answer my questions and even called at one point when I requested it.
That said, after going through this, I am of the opinion that an aluminum rear axle should not have been specified for an electric fat bike. It wore down prematurely taking out the bearings and the ratchet ring in the process. Replacing the entire hub was not an option as SUNringlé does not provide an option with the steel axle installed. The more jaded amongst us may say that this sounds like a planned obsolescence to sell more bearings, axles, ratchet rings, and ratchet ring tools...
Truly, if you want to save yourself a lot of pain, try to find a shop that will service the hub for you. That said, finding such a shop may be challenging. I live in Toronto, Canada and I lost track of the shops that I contacted to get some help with removing the ratchet ring as I did not want to spend another CND $80 on a tool that hopefully, I'd only have to use once. Turns out, there is a dearth of knowledge about SUNringlé hubs in this city. Thank God, I finally found Agustin in the service department of BikeSports in Newmarket, ON.
Fingers crossed that the problem is solved.
Cheers, CubeHead