IntelliJ is slow to start up (though I've no idea why that would matter for an IDE). And when indexing and building it can be very demanding on machine resource

IntelliJ is slow to start up (though I've no idea why that would matter for an IDE). And when indexing and building it can be very demanding on machine resources. But I've never found it slow in any respect that matters for doing actual work. For everything that matters (opening files, project-wide search/replace, refactoring, typing latency, looking up docs, code navigation etc) it's easily competitive with lightweight editors.