Hi Thargor,
The usefulness of the courses at dbs probably depend on your level at the start. Having completed both diplomas (advanced dip also), I would say they vary greatly depending on who is giving the lecture. But, I don't think that there is enough in the course to enable you to be confident of portfolio management when you're finished.
I don't want to be too harsh, but I thought they're abit light and I think something more intensive would be more effective in the long term.