When running a merge on a branch into a trunk working copy using the Version Control-->Integrate Project, IDEA sits there doing nothing for quite a while (a couple of minutes) before any activity appears in the popup dialog. So long in fact that I almost logged a bug saying that I thought it wasn't working at all.
Running: svn merge -r11191:11237 https://svn.blahblah.com/projectName/branches/release-555P2 in the root of a trunk working copy gives almost immediate feedback about files that need merging.
Why the long delay in feedback to the user?
Clicking 'Cancel' also takes 20-30s to return.