I also love being able to experiment on them!
This one was for a friend of ours who wanted a normal German Chocolate cake, (AKA nothing fancy or fondant covered.) But that's no fun, so I made Swiss Meringue Buttercream. I love how it tastes, but haven't offered it to customs yet, because I'm still in the experimenting phase.
And this is why:
The darn stuff has a much lower tolerance for heat than the buttercream recipe I'm currently using! I did what I could to fix it, using the back of a spoon and the leftover frosting. (I wasn't in my own kitchen when it slid of course)
On the positive side, it was delicious!!