Boost.python vs Cython for C++/python interface
Considering my application, which mainly is a scientific
That pretty much means Cython. Cython was made almost specifically for that very purpose. There is a video on getting started with on from Enthought. Enthought is a company that specializes in scientific calculations.
Cython has a very good integration with Python that is unmatched by C++ or C (you would have to use #include <Python.h>).