You will get the better part of the deal if you trade for those DD 2512s instead of the 20.1. Unless you get cash on top of 20.1. It just sounds like such a big downgrade from a Stetsom to a 20.1. Are you getting any cash on top?
The battery has been great for me, I can go at least a full day without having to worry about a charge.
I have 2 pictures posted up, PM me if you need some more.