Ozz,
The trouble with these (I love this question by the way) requirements, mild winters, moderate summers, well, every place has summer and every place has winter. By definition, I believe that summer is warmer and winter is colder.
Another part of the equation, is of course, where can you afford to live.
And, what is your personal comfort zone.
Do you like really warm weather, or is the colder stuff more your calling.
We love Michigan in the summer, Wisconsin, Minnesota were both wonderful the summer we were there. But, both have snarly winters. Mission where we love to be in Jan, Feb and March, is lovely, except for about 10 to 15 days (most years), when it gets downright miserable from the mist they call rain. YUCK it is nasty. That is their winter, glad in most years it does not last long.
But, all that said, I cannot wait to hear some responses from those REALLY in the know, our TX MOC friends.