It is ok, and nothing more.
If you would like a present view of the web Ahref doesn't provide. It is a GREAT tool and idea, but it has a major sit back that renders it almost useless. It is crawling and updating the data in a speed that make me believe they use servers that were already outdated in 1998. If you do website and keyword analyzing the last update for keywords is up to 40 days old. For backlinks they constant give wrong data. They will claim 10% of the links as lost, and then if you go check on the websites the links are still there. I would give it 2½ stars, but if they fixed the update speed of links and keywords, as well as reduce the false LOST link status, I would give them 4-5 stars. I use other similar tools that somehow can update everything almost on a day to day basis.