We use doc-link to route all AP requests for approval. We also use it to store and route documents. doc-link allows us to store and manage all documents in one location. We are also able to set up a workflow for the document types to route for approval or different processing.
Document workflow can be confusing as it is all a workflow chart. Bigger worksflows get hard to follow in the flow chart. One solution we use is to break the workflow into smaller parts that all work together.
AD connections can be tricky to set up.
Customization is great but it would be nice to push the same customization to all users of a certain group and then lock it down.
We were using both doc-link and OnBase for document routing and storage. We did get rid of OnBase and moved all documents to doc-link without issue. By choosing to have only one document management software we were able to save money in software costs.
If you have a image document you need to store or run a workflow on it is a great tool. The key is you have to have a document. You can't run a workflow if there is no document. It should not be used just for processing a workflow without a document.