I installed it, and it crashed the browser on every page. I think it has some bugs still to work out. It took me longer than I'm proud to admit to figure out why pages weren't loading properly and the tabs kept using too much memory.
Yeah, I've added a lot of communities over the past week or two. I must just be a dummy with this extension because I can't see that it's doing anything. Not crashing me for sure, but I still have to copy->paste->search to add communities. Which isn't awful, but one click would be nice.