To be honest, I doubted the ability of SerpWatch to stack so many useful features in a new tool but since I've been following their work before I bought it (I wanted to buy it in the first round of AppSumo sales). However, with slight hiccups due to the AppSumo sale, SerpWatch has worked like a charm for me.

If I had to highlight a couple of features I like the most, it would be:

1. Google Analytics integration
2. Slack notifications
3. Ability to report wrong rankings

The last one might seem to hide a con, but if they are willing to listen to their customers and admit they made a mistake, they have my upvote.