It all depends on their importance to your overall picture. If you are VERY dependent on AUs, it could have a big effect - on util, length of history, average age, mix of credit etc, etc.
DW and I are two thirds of the way through converting AUs to Cosigners.
The slide from grace is really more like gliding
And I've found the trick is not to stop the sliding
But to find a graceful way of staying slid