With one, you have to be cautious against infrequent exaggeration. With the other, you have to work your way through their constant denial. Both are not on point in scale of truth, and both can be used to completely subvert it for some intended purposes, but I think one is closer to the truth more frequently and by a lot than the other.
You can definitely pick the exaggerating side to start with, then work your way to the truth as much as you can from there and you’d be closer to it than starting with the other one, having a lower rate of going astray.