I just recently removed a 7 year old (in service) factory Ford Group 96R flooded design battery from my wife's Mustang, still working but with the "eye" showing red instead of green. I just didn't trust how much longer it would go and picked up a Group 48 AGM battery from Pep Boys for $99 with 4 year full replacement warranty to replace it.
The factory Mopar AGM Group 94 (H7) Johnson Controls battery in my truck is still going strong after 5.5 years in service.
Both have battery blanket insulation FWIW, these are the first vehicles we've owned that had that feature. I picked up an aftermarket battery insulation blanket kit for the Group 48 AGM I put in the Mustang. The Mustang battery tray is attached to the firewall, a design that assures the Mustang battery is exposed to plenty of heat.