I have to agree with Tom on some of these points. I have several places where I used a curved switch in those situations as the numbered switches didn't work well. In the places I used the #4 switches it was because I had two concentric loops so a curved switch wouldn't have fit in to do the crossovers in that case.
I spent a lot of time with the track planning package trying to see what would fit where. Even with that, I still had to make a number of modifications on the fly when it came time to actually put track down.
It's all in the fun of the game. 
