Also chiming in to say I used Zotero for my Master's thesis and I was happy with it.
With some plugins (I don't remember exactly) I had a very nice pipeline of "find paper on the interntet" -> Zotero -> automatically updated .bib -> trigger rebuild of Latex document to PDF -> automatic reload in PDF viewer.
The UI is somewhat dated but the functionality is great. Nowadays I would probably choose Citationsy, maybe only because I find the UI more aesthetically pleasing.
With some plugins (I don't remember exactly) I had a very nice pipeline of "find paper on the interntet" -> Zotero -> automatically updated .bib -> trigger rebuild of Latex document to PDF -> automatic reload in PDF viewer.
The UI is somewhat dated but the functionality is great. Nowadays I would probably choose Citationsy, maybe only because I find the UI more aesthetically pleasing.