From our point of view, people should use best of breed tools that are specifically created for workflow and collaboration purposes. Services that have both workflow and contract management tools are not usually as good as the previously mentioned, because they cannot keep up with the technological advancements that collaboration tools are facing. Tools that specialize in a smaller area (but can be integrated into other products) are usually state of the art.
So, ContractZen focuses only on managing the final (i.e. approved) documents, so we do not have any document creation, workflow or collaboration tools. However, we have integrated several e-signature services into ContractZen (like Adobe Sign and Assently) so you can send your documents for e-signing straight from our service. You can also track the statuses of the signatures in ContractZen, and the signed documents will be automatically stored in your account so you can easily find and manage them afterwards. In addition, Adobe Sign and DocuSign have workflow features in their eSigning service. You can, for example, choose the order in which the signers sign the documents, and add approver(s) to the signing workflow (so you can first send the document for approval, and then for eSigning).
We recommend you to evaluate which tool is the best match for your needs. (For example, you might want to check out what kind of new collaboration tools Microsoft Office 365 and Google Docs offer.)
ContractZen also has an API which can be used to integrate our service with any other system. Please contact us if you want to hear more.