Is it worth what?
One negative to Adsense is that some people object to any ads what so ever. What can you say to them? I say "Good luck finding an ad free site, buddy"
Some people detest Google particularly because Google knows so much. An awful lot of us are running Analytics, so potentially Google can track your web activity across a wide range of sites. Some people are very paranoid about that and the ads just make their blood boil. Again, I say good luck finding a site that doesn't use Analytics today - they are few and far between.
Google ads often add value. They are often exactly what a visitor might be interested in. That's good for you and Google.
Another negative to Google is that unless you are bringing them lots of money, you are effectively invisible. They just do not notice the small fry. I make $700-$800 a month from them and they don't notice me; you can imagine how unimportant the $20 people are. Make $10,000 a month and, yeah, they know you, but few of us will ever do that.