I've been the Firefox sidebar for ages and I find the new one to be a big improvement in terms of usability, but I'm curious about other people's experiences with it. Do you use the sidebar? Which parts of it do you use more (history, synced tabs, bookmarks)? Have you tried the new one and does it work for you? If it doesn't what do you think is missing or could be improved for it to be a full replacement of the old one?