you can never know you'll get a ch, you have to get good at guessing when you will. but you can always end up in a really bad spot if you try. backdashes and jump outs are a good example. so you want to know the places your opponent is likely to backdash or jump, but you really can't always know. and it's probably a good idea too to try to limit it to when you'll get a lot out of it. charge and meter for example. no charge, no meter, stay away.
if you look at konan, you'll see he uses it not that much, and often doesn't work out for him.