Put one in a week ago and got to see the cold-start scenario one morning shortly thereafter. It was in the low 40's (F).
It's pretty cool the way this battery works, and opposite of a normal lead-acid battery.
First attempt, nothing. Wouldn't even try to turn the engine over. With the stock battery this would mean it's time to bring out the charger.
Not so with the Shorai.
Because I had read all about the battery prior to purchase, I knew to press the start button and hold it for ten or fifteen seconds to warm up the battery.
Eureka! It cranked like crazy on the next attempt.
Technology is so kewl!
Another happy customer!