Easy to implement, easy integration with all our applications/systems like Salesforce etc., Very good support from their team of experts in this domain also available for free consultation - can't complain about that! It's not something I have faced so far but if any issue arises we will get it resolved very soon as per my experience working closely with them before they came up (I am sure).
We use diffBlue cover mainly because its an excellent tool when you are looking at some specific data or insights which may be difficult otherwise due to volume & complexity involved while doing manual work / analysis process.