I think you'll like the Steck one better. The walls are higher/taller, so it's really closer to scale for Playmobil figures. The sysX castle walls really are that much smaller (too small!).
Not to mention that, you can expand this much MUCH easier. You can also get the Steck house that DS has to go with/inside it and the bakery next year. Oh, and the barn.
As you can see, soon you have a medieval village started.
They really needed to have made a Steck Church (yes, you can build one and yes you can use the new/discontinued one) but it's not the same. LOL
Congrats!