I just finished reading the novella (a year and a half late but oh well) and while I loved most of it, as a fan I think the biggest 'issue' I had was the ending with Vin and Kelsier. I think both of their actions were in character (though I thought Kelsier may have been more wanting to go to Mare) but in my head I had always enjoyed picturing Vin and Kelsier reuniting in the afterlife for longer/forever and that Kelsier would, well, stay dead. Guess it will take some time for that to absorb!