I use zotero and I really want to like it, but it's not that good. The tagging functionality seems like an afterthought, the bibtex support is only reasonable with betterbibtex and even with it I have issues. For example journal abbreviations don't work consistently, every start up I get told that the betterbibtex styles have changed and I need to restart zotero... File management is also only bearable with zutilo, and I still get issues with sync and somehow some file locations getting messed up.

The whole note taking experience is also quite soso.

I really wish there was a good bib manager around. I don't want to go into a proprietary silo (ruling out mendeley endnote etc.). Jabref is in many ways better then zotero when one uses bibtex, but unfortunately some parts of the UX are not my thing. The best app I have used was docear, the concept of a Mindmapping app together with a bib manager was great however it is unfortunately not maintened any longer.