While it may appear that they move at different speeds, they actually move at a constant speed until they reach the final arc and fall to the bottom. However, certain springs enter the screen at different places, which allows you to tell where a spring will land far before it actually touches the first arc point. This is useful for telling when you have to retreat, because really, if you leave early enough, there are only a few springs that can actually kill you. Like others said, study the spring theory thread and practice a savestate for a long time, you will get it!
