Just my thoughts, with no scientific evidence to back it up............Personally I don't want my temp to exceed 70 degrees. I understand logically that I'm probably getting a little on the OCD side of the allowable side of high temp, but I just don't really want to take a chance. I also realize that in certain parts of the country it is going to be much more difficult to maintain a temp of 70 degrees or less. However, when I think about the fact that I have several hundreds, if not thousands, of dollars to lose, I am willing to invest the additional money to insure that I keep the temp at a level that is going to give me piece of mind. Again, this is just me.........it may not apply to anyone else..........