Avenue from VC in one example, gathers SAP VC configurable product data, exports it in XML and makes it available to other configuration companies to transform, compile the exported VC product model and upload the translated model into the configuration solutions administrative area. What that means is your VC Configuration model no longer is restricted to just SAP. Avenue from VC is used with three different CPQ solution providers enabling SAP VC customers to have their Variant Configuration product model data operate outside SAP on mobile devices and the Web. The VC behavior and execution are the same. There are differences but those are due to the differences in a CPQ application capability. The UI is very different and the platform is different. But, your investment in the SAP VC is preserved.
If you are a SAP Variant Configuration customer/user and you would like to see your SAP VC configurable product models extracted from your SAP system and function using the same behavior as the VC but outside SAP ECC or CRM, there is a way. Of course, if you want to change the UI, that can be easily accomplished in a CPQ application or custom solution without impacting your VC Model logic.