Rated 3 out of 5 stars
Consider very carefully before using this add-on, it is very buggy and has limited functionality. I only use one Gmail account plus local folders and wanted to be reorganize all my Gmail into a systematic label/folder structure.
I had a bunch of filters using tags and exported them then edited the filters to folder/labels and ran it through my Gmail/All account. Apart from crashing my modem, this worked, but when I tried to re-import my old tag filters it would only import them to the local folders account. [scream!]
I found a work around by exporting from local folders and re-importing to Gmail. But if I had multiple accounts I do not think I would be a happy bunny.
Finally once the obvious bugs are fixed, I think an enhanced filter editing capability would turn this add-on from a liability into something really useful.