You happened to write a word that I was PLEASANTLY SURPRISED with the Asus Transformer tf300 and dock.
I gave the unit to my son to drive around and see what he thought. I didn't supply a charger. He played with it during that day and then it sat for a week all the while never connected to a charger.
What usually happens is the unit goes dead. I was amazed that when I fired it up after it being off the charger for a week it had more than 84% charge left. This is really good news for those that must have long battery times.