DubBot's usability is great even for novice users. It's simple, functional interface has barely any learning curve at all and that's important to me because I have almost 2 dozen users in the system. That fact also makes training really easy, which allows me to focus my training on the metrics I care about most. Once my users get up to speed, and that's very quickly, they run with DubBot's features.
Also, I have to mention their responsiveness. The DubBot staff are super-quick to respond and very open to innovation. Their communication in general is excellent and transparent. Review collected by and hosted on G2.com.