Love it!
As a scientist I do a ton of online research, and I have not found anything better to organize and keep URLs, or to save an ongoing search in a split second when I need to go and close the browser. The glitch of the last update has been fixed, as indicated by the developers. You can backup, which I recommend doing once in a while if you have a whole library saved in OneTab like I do. It takes less than 10sec.