Simple is definitely best I think, when it comes to railroad layouts. I am in the process of clearing space in my basement for my own railroad empire, and each set of plans I come up with is simpler than the one before. In addition to creating less headaches when it comes to laying track and wiring, it leaves more space for scenes featuring the rest of the Playmobil we have.
My plan is to have two loops, each at its own different level. So there will not actually be an incline since each loop is self sustained, although there will be a high line and a low line.
Good luck, and please keep us posted as you progress. I plan on making a run to the lumber store this weekend, so hopefully I will have some photos to share soon.