Compared to jedit, stability is a huge issue as IntelliJ seems to take a “move fast” approach which makes each update risky especially given their recent QA issues.
IntelliJ also doesn’t scale very well for large code bases due to the number of features it tries to provide. Basic things like project opening can take tens of minutes while jedit takes seconds (if that) as it’s not trying to build a syntax tree at load time.
This. The feature set in their suite of IDEs is amazing. The occasional lag though, man, sometimes I wonder if they actually use their own IDE. I don't think Java is to blame either, I have Java apps with much higher heaps and lower pause times...
(Not IntelliJ, which is horrible in every regard.)