i know i did that was the point. They have the same backstory but Lots o is a much more intidmidating villian as he is more human.
Given that he's a toy, calling him more human is a stretch. In terms of emotion, I would agree that Lotso has more emotion than the Emperor, but Palpatine is so much more than the bear.
Remember that the Emperor was in complete control of the entire galaxy. Lotso was in control of a bunch of toys that had no real bearing on the outside world. They were both in control of their own worlds, but Palpatine's actions had a much greater effect. Plus he could fry Lotso at will.