I am using zotero for some time and have already several subcollections in my library, each corresponding to roughly different topic. I thought that splitting my library into such subcollections is good idea but now I can see it is not: I encounter citations which thematically fit to more than one of my collections. Well, of course I could avoid this problem by not using subcollections but tags only and single master collection. But what would happen when I reach some thousands of citations in that collection, moreover each containing the pdf attachment of 1MB on average? Will zotero/firefox handle it smoothly?

Thanks in advance for your suggestions,
.kosa