switch backflips are nice because you can spot your landing as soon as you take off and not lose sight of it at all. if you dont set your flip correctly, have poor timing popping off the lip, or are looking over your shoulder and start rotating that way, then i can see it not going so well but for the most part a switch backflip is and easily overlooked trick that isnt too difficult.. if you are comfortable with backflips and comfortable riding switch then its not much more to put them together.
im guessing you mean switch frontflips? those are going to be blind pretty much the whole rotation..
here are a couple videos to help you picture the rotations of both( they are doubles/ triples but you get the idea)
mmmmmh rory bushfield's sw backflips
christian bieri doing his thing
Gravity is a harsh mistress.