I've been using Documentum products for seven years, starting from version 6.5 SP1.

In my experience, the starter product of Documentum is xCP 2.x. It allows you to create amazing Documentum-based applications with just a few clicks on its workbench, no need to write a single line of code.

It's an excellent solution, I totally recommend this product if you need a content management solution. But make sure your revenue will cover the investment in licenses.