This question is borderline TeX related but I think it may still be relevant.
Apart from the fact that the latter is comparatively expensive, both softwares seem to offer next to no BibTeX support. Sure, they allow exporting (or even maintaining)
.bib files mirroring the library but those files aren’t really usable in common scenarios (e.g. when you need to manipulate the typography, when specifying the sort key by inserting TeX commands in the authors list, or when you want to customise the citation key).
On the other hand, these citation managers have a very handy feature: when you drag a PDF onto them, all metadata (title, author …) of the article is automatically imported from online databases and doesn’t need to be added manually or by explicitly downloading an exportable citation from the journal website.
So, Is there a citation manager which plays nicely with BibTeX and has automatic metadata import?