The scariest thing Is that last time a lot of that debt got absorbed by government (under the form of bailouts, fed balance sheet growth etc) but they haven't done digesting what happened back than yet.
If we where to experience a second debt crisis like we had in 2008,... The medicine we used back than will be out of commission, and the results will be far worse than they where in 2008...
I do however agree with the FED statement that this debt is different due to a lower interest rate.
Your capacity to pay off a debt des not depend on the total amount owed, but on the monthly payment due. A high principal with a low interest can be easier to pay off than a low principal with high interest.