I've found that every version of GIMP for the Mac is annoying. Most recently I found out that I cannot, through obvious means that worked before, paste a second image onto a background and move it with arrow keys. And GIMP 2.6.8 for Mac (I'm running Mountain Lion) retains the "Display the fonts dialogue directly behind its parent dialogue where no one can see it." bug.
Previously it seems there has been one persistently obnoxious feature - in previous versions, this has included having an "open file" dialogue sorted FIRST by number of characters in name ascending, and THEN alphabetically, making a perennial pain to find a file without (or even with) counting how many characters are in the filename. However, this time they've outdone themselves for PNG web-based manipulations for users consuming and producing PNG who really don't want to opt-in to the "Do all your real work in XCF, then at the last minute export the format."
Is there a Mac-available GIMP fork that either does not subscribe to One True Format, or else allows PNG to be a One True Format?