Although I fully agree that an aeros course will improve your handling skills to no end, handling skills are not the only things I would consider part of an advanced PPL.
I would also suggest:
- Advanced navigation (well beyond what you've done on the PPL course, using anything from pure DR to advanced GPS tricks)
- Flying with limited visibility/entry to the IMC course
- Minimum level flying/navigation (aka "scud running", but done without busting safety minima)
- Cross-channel checkout and other international flying
- Advanced/max performance landing and take-off - visiting short grass strips and such
- High altitude flight - proper leaning - oxygen use