[cormacrelf]

Papers had two downfalls for me, which were that it had no functionality similar to Mendeley's sync to .bib option, and it made weird citekeys when you manually exported lists.

Using Pandoc and its referencing tools requires .bib files, and Mendeley's automatic .bib export means I can just type citekeys and expect them to work. And if you want your text to make sense as a markdown file, you want your citekey clean and informative. It's been a while, but I think Papers used citekeys that didn't conform to any sort of spec (something like :_blah instead of Author:DATE), and pandoc simply couldn't read them.

I use Mendeley now. Doesn't have the cool research tools figured out as well as Papers, but it does what it's supposed to do, which is to store my citations in a way that makes it easy to put them in a paper.