NetCURL 6.1 is built as individual modules, so it is possible to communicate directly with each of them separately. If you are sure that curl for example is always available, regardless of what platform you put your code, the CurlWrapper can be used instead of NetWrapper.
The unittests that was built initially, was built in a way so each module could be tested separately. It was in the second step the MODULE_CURL was written, but with the new name NetWrapper - which is the module that is self selecting "best available driver".