Extremely good. I use this o get the same depth of info I would otherwise only get from a big 10lb dictionary. Have had it and relied on it for nearly a full year now. As good and better than the expensive dictionaries you can get. Buy it. No, Im not affiliated and have no clue who makes it -- something I ten to wonder when I read good reviews.
Also, the depth is good for a beginner or someone who is fluent and has studied the language and translates professionally, and wants to get even into the nuances of the language for communication or out of simple academic interest.
MoEzekiel about Dictionnaire de français TLFi