A 160 degree stat is bad because your engine wasn't designed to run at 160 degrees.
It is designed to run in the 190s.
People only use 160 degree stats because of a misguided belief that it will make a car run cooler, but it doesn't.
I will post this example again:
A 160 stat opens at 160 degrees.
A 180 stat opens at 180 degrees.
At 210 degrees which one is open?
That's right..... Both. At 210 degrees your engine doesn't know or care if the stat is a 160 or 180 because they are both open.
So here is what that 160 stat is doing for you.
It is lowering your gas milage because your engine is spending additional time below it's optimal operating temperature.
It is causing additional wear because your engine is spending additional time below it's optimal operating temperature.
NOTE: You will have a bunch of people here tell you that "I have always ran a 160 stat and have never had a problem". Ignore those people because they can't see the big picture.
The additional wear on the engine happens, not up front, but on the tail end. Lets say you got 150,000 miles out of your engine, before needing a rebuild, running a 160 degree stat.
Driving exactly the same but running a 180 or 190 degree stat, your engine may have went 210,000 miles.
Now back to your cooling. Your perceived problem (because I think your temp is fine), is airflow. This is indicated by the rapid cooling once you get moving.
