Just did the Munich marathon... it's somewhat smaller and low-key. Very well organised, as you'd expect. Olympic stadium finish, if that matters. Quite flat. Nice stretch through a park at one point. Munich is a pretty city with excellent public transport. You need to have faith in your transport planning on the morning of, as other runners will be boarding trains/ trams that go in the opposite direction to the half mara start.
I didn't like that the water and sport drink was served in cups. (Wearing the water isn't bad, but sugary sticky all over me makes me sad.) On the plus side, they do have drink-on-course tables where you can deposit your own fluids in advance. They weren't overflowing with bottles, so that should be a viable option.
Have fun, whatever your choice.