In addition to what the others stated, once the t-stat is open, it will remain fully open, where the stock unit will attempt to keep the temps around the factory 205-210 range. The low temp starts to open at 160 and will keep the car in the 180-185 degree range, some 20-25 degrees cooler than stock. Lower coolant temp=lower oil temps, which is a must on these cars. I replaced mine a year and a half ago and am very pleased.
More here:
http://www.lnengineering.com/lowtemperaturethermostat.html