A criminal conviction doesn't just mean fines and incarceration -- it also means a lifetime where that criminal record follows you everywhere you go. That can ultimately limit the opportunities you have and make it much harder to put your past where it belongs.
Some people have said that criminal trials are often won and lost long before the jury is seated. They're talking about the way pre-trial motions can affect the outcome of a case.
Getting charged with a federal crime is terrifying. However, many people fail to realize exactly how much trouble they're really in, thanks to the onslaught of mandatory minimum sentences.