By far the best gmail addon I've used (especially since the previous one I tried didn't allow changing labels, which is a major part of my workflow). There's not much that can be said as for the large part, it "just works" as expected (and with a good feature set). Perhaps if there's one criticism it's how a variety of actions can't be done from the toolbar window and will instead open a new tab (slower). Still, it's the best gmail addon I've used, so view it worth 5 stars compared to its competition.