I have rode that route a few time and it is a good route.
As I 'm from Indiana I took 421 through Madison In to 55 to interstate 64 east to exit 48 to route 151 to 127 south. In the south part of Ky 127 is got some curves.But road surface was good.
There is a good place to eat just a few miles south of Liberty KY on the left side of the road. I'm sorry but I forgot the name of the restaurant.