Radian6 is an industry leader in social media monitoring. In terms of the results returned from the web at large I've always been extremely satisfied. They manage to return just about every company and entity mention out there. The widgets are quick and easy to create and provide C-Level teams with an overview of information they need to know while letting those using the tool daily dig deep into the data. It's the best of both worlds. I will say if you aren't used to a dashboard tool the setup and creation of this will be a bit of a learning curve but nothing you can't handle with the support of their customer service team.
The profile setup is relatively easy although when it comes to clearing out spam results from Facebook it is a bit of a manual process. This is out of Radian's control as it is an API issue on Facebook's part.
I find their proprietary influencer tool isn't very helpful or accurate. You can change influencer attribute settings in the report and it does give you results however it isn't fully comprehensive. Instead we use the tool to monitor conversations and hashtags to identify influencers.
Radian6 is a great tool and service that I have come to rely upon. With many competitors coming up in the marketplace there are certain one-off features Radian6 has yet to start incorporating, for instance returning Pinterest results. This is something I hope they address and continue to improve upon as they are a Salesforce company and have been an industry leader for many years.