Never had a problem with any genuine Gates belts
Have seen fake Gates sold on ebay
I rarely have problems with aftermarket belts but mine all come via my wholesaler and down here warranty is a legislated mandate so it is rare to get a bad part from them
The problem we do have is too many people trying to make too much profit from too small a turn over
So it is nothing odd to see OEM Branded belts at prices up to 5 times that of quality aftermarket belts
If you get the right GAtes belt it should have a part number that ends in BR ( Blade Runner ) which will have the same or higher specs than what was originally fitted