If you can't make the core pandas code decently fast, dask won't save you.
I've had success using it on non vanilla stuff (i.e. code that could not get converted to play natively with numpy/pandas structures)
As a bonus, the nice profiling tools (built within dask) have also helped me improve the performance of the code.
See https://distributed.readthedocs.io/en/latest/
If you can't make the core pandas code decently fast, dask won't save you.