Get the bigger once. There were a lot of guys having trouble with the smaller battery because of all the electronics in the car. The Mini battery is another option. It's suppose to fit perfectly and is a little larger.
Let me get this straight... You are swapping out parts designed by some of the top engineers in the world because some guys sponsored by a company told you it's "better??" But when you ask the same guy about tracking, "oh no, I have a kid now" or "I just detailed my car." or "i just got new tires."