Anyone have an answer why the XLR went back to the old style battery terminals?

The side terminals were known to leak in the corvette. I have two of them (XLR is based on same car) and it was a constant problem. I don't know if this is the reason but it makes a lot of sense.

I agree. I have a 1991 Vette that has gone through at least 6 batteries, or more (I lost count). Sears has lost money on their Diehard guarantee with me.