[George Maz]

Totally agree with Hib.

Odyssey & DieHard Platinum are the only choice for my cars, boats, jet ski's. And for the same reason stated, the Optima can't handle repeated deep discharges. The Odyssey (formally Hawker Military Spec) is rated for over 400 deep discharge cycles. The extra price for 99% virgin lead is worth the peace of mind. My Red Flop Optijunk was nothing but aggravation, but it works well as dead weight in my snow tractor now.

I was searching the preferred ODYSSEY size here today because I noticed my recently purchased ZR-1 was slow to crank and the dashboard dimmed. This condition doesn't occur with an ODYSSEY equipped vehicle, so I'm eagerly swapping out the "old tech lead acid" for AGM.

I even splurged for the 25amp ODYSSEY AGM battery charger (rebranded Schumacher) a few months ago.

Sears here doesn't even sell Optima anymore, too many warranty returns so they dumped them in favor of making DieHard Platinum an AGM battery made by ODYSSEY (grey case or Marine blue case) All made by the parent company EnerSys...everything else made by Johnson Controls, which I'm sure you've seen their white vans running around replacing all those lame batteries.
DieHard Platinum has limited selection of sizes for specific applications, just call ODYSSEY directly and speak to the nice lady about your application...she got it right every time so far. If you can find your battery among the Platinum selection, try buying on a Friend's & Family Sunday for additional discount.
My advice on the side terminal style installation is do it yourself. 90% of side terminal issues were related to excessive torque when installed by untrained store personel. 10% was vibration issue.