...........I'll answer my own question.
Had a first hand experience last night with a non-failsafe thermostat. My daughter's Camry overheated on the Mass Pike on the way home from college and she was dead in the water. The thermostat failed closed. This is a perfect example of why a failsafe style is the right choice.
A. This road is very dangerous to break down on. Thankfully it was daytime and there was a grassy hill where she stopped so she could get away from the roadway.
B. There was always the chance that she fried the engine ($4000 replacement)
C. I wouldn't have had to leave work early and drive 2 hours to rescue her.
It's just not worth the risk to not use failsafe style products. Worst case she would have been without great heat, maybe a little less fuel economy and if ignored for a considerable period of time...maybe damaged the cat.
NAPA did not have failsafe thermostats so I installed what they had and will install a failsafe tomorrow in her car as well as her sister's Camry and my wife's van.
Jay in MA
Sounds like you got a defective T-Stat.....like everything, it happens.
I believe the OEM stat is fail safe...hence the cost.
Would you have preferred to fail open or closed?
I won't ever use a Fail-Safe thermostat again. I installed one in my Prizm late last fall and it locked open in just months, on a very cold day too. I do not have any problems with my cooling system so it had to be the thermostat. After replacing it with a normal one everything is great.