I just tested the Zotero Firefox plugin in TenFourFox after the latest (17.0.5) update on a G5 dual 2.3, and was delighted to see a huge improvement in sync speeds (as promised, i.e., all that stuff about online storage services in the readme). I am shortly off to install the update on a 12" G4 PowerBook in order to see how it behaves under the new regime. Well done!