Obviously every contract and situation is different, but I will say that other airlines with training contracts have been able to enforce them. I would definitely not assume you will be able to get out of it! That's just stupid and risky. If you are lucky, you'll get out of it after paying legal fees. You might be able to set up a payment plan with low payment, but to think you'll get out of it because of precedent from past issues that are totally unrelated...

I know that good ol' Great Lakes training contract was fought all the way up to the Supreme Court of Wyoming, and the airline won. How about that for precedent.