Autozone Duralast Gold it was. There is exactly 1 size/form factor that fits the Jetta TDI, so it was an easy decision. Had the cheeful folks there test the battery and alternator, which both checked out fine. He recommended sticking with what I had. I says to him, I says "Wellsir, I'm buying a battery today. You want to sell one?"
The new battery goosed the ol' Jetta into life with alacrity this morning, so I'm pleased.
Der Deutch put an incredible amount of STUFF on and around the battery of that little car. Took 5 minutes before he could actually put a wrench on the terminals. This was not as bad as the person ahead of me in line. They had to have a brace and the windshield washer reservoir removed before he could actually even SEE the battery. Chevy Malibu, I think that was. Reckon how they put jumper cables on one of them?