The most useful feature in produmex has to be their quick response time when it comes to support issues that I have with my account as well as any of our customers accounts. Also they are very helpful at explaining things if you need help setting up your own system or integrating other systems together like Salesforce and Sage 50 Accounts Payable for example. We haven't found anything we dislike about them so far but there really isn’t much either! Our Account Manager helps us create reports daily which allows her to make sure she can keep an eye on what needs attention first hand rather than having someone else send out emails every week asking questions.