What is the operational difference between the stock 195 degree thermostat, and a 180 degree unit? Does changing to the 180 make any kind of difference?

Thanx!

Nothing really noticeable except maybe if you drive in really cold temperatures, your heater will not heat at a very high temp.
180 will be fine as long as you don't get sub 0 temps, in which case you should pop the 195 in for the winter and come spring swap in the 180.

Your engine will start to cool sooner but unless you have aftermarket programming or a fan switch to kick the fans on earlier your engine temp will still get warm on a hot day. It will tend to stay cooler at high speed due to the airflow over the radiator.