After a restless night today was much better. I accidently got the focusscreen out of my Canon 5D mark II, and I was under the impression that I had destroyed my camera. I went to the photostore as they opened this morning, and they replaced it for me after I bought a new one and now my camera works perfect again. They did not have the standard that is delivered with the camera, but I got a type called EG - D, which has a grid design, and I love it (being into architecture and other motives where its helpful with the lines and cross).
As I was getting the focus screen on the shelf in the store, I saw that they had a type for manual shooting with split screen. This appealed to me, since I also have a 17mm TS lens, and I am seriously thinking about getting the MP-E65.
Finally a question arises: Would a split screen focus screen be ideal? Would it not be the best of two worlds, or would the split screen focus screen interfere somehow/distort regular AF shots?