Hi,
The biggest difference is that the Qlik REST Connector is free, but you have to licence Qlik Web Connectors, for anything other than the standard connectors.
Some of the connectors that are included in the Qlik Web Connectors will be talking to the APIs using REST, and could in theory be re-written using the REST connector. However, by using Qlik Web Connectors all of the heavy lifting of doing authentication, storing credentials, maintaining state, cleansing output etc. etc. etc. has been done for you. Furthermore, the Qlik Web Connectors will have been rigorously tested, and the developers are looking out for any changes to the APIs they connect to that will require a change to the code base. If an API does change without warning there will be a large number of users affected, and a fix usually appears very quickly.
If you have written your own connection using the REST connector then you are on your own and could very easily spend a lot of time developing your connection, and it may not be robust going forward.
If you are connecting to a REST API that you manage internally, to your own intranet for example, then there won't be a Qlik Web Connector for it and you will be well placed to build a connection to it.
If you are connecting to something there is a connector for though then I would suggest that the buy vs. build argument goes heavily in favour of licencing a connector.
Hope that answers your question?
Steve
