I could not compare & test the durability & longevity of the cassettes in a accurate & scientific way, but here is my experience with it so far. I have been swapping between 3 wheel sets, and various time of use, only way to accurately test it is a machine with exact same abuse.
The cogs eventually bent/twisted, but it took much longer than on the XT casette,
the Sun Race Cassette is more flexible, but also more resistant to ”permanent” bends.
I have 3 wheel sets I rotate, when one needs a service or something is wrong I can just swap, so I haven’t used the cassettes 100% equally amount of time.
I am not sure if the flex in the FuelEx’s that did this or if its the cassette’s fault.
it was more resistant to blends but is more flexible than XT cassette.
I have of course regurally chainged the chain when it got to 0.40mm stretch. and lube the chain well, an done every htign correctly.
The Last ride on the last cassette:
I worn out 2 of the tree cassettes, and June 2018 I worn out the last one.
The cassette was so messed up, that the chain dropped to the smallest cog.
I knew the cassette was going to wear out soon, and it did,the chain dropped to the smallest cog. The hanger was bent too.
the smaller cogs are have bent teeth & twisted teeth, some of the cogs are bent too.
there is no way I can twist the teeth back to be straight with any tool I got. if it was just the cogs a screw driver would probably do the trick, it did before on several XT cassettes.
I had to put on Xt cassette I had.
The Sun Race cassette was more resistant to the abuse The Fuel EX frame set put s the drive train trough, but eventually it got abused too much.
Back on the Sun Race cassette
The backpedalling issue was gone when I went from 34t to 32t oval chainring.
I could pedal backwards without the chain dropping or skipping or any high noises.
The range seems to be what I was looking for.
With 11-46T x 34T oval I found I needed a smaller chainring, so I got 33t. I could have gone for bigger cassette, but I did not need the high gear the 34t offered. And I will stick with sun race 11-46, as Shimano xt m8000 does not offer the a good transition to the largest cog.