The Abit ones are about 1-2 years old and the Gigabyte ones are within the last 3-6 months or so. Northwood and Prescott basically. It might be because they're both brands usually aimed at the overclocker/tweaker crowd though.

Yeah. It's a good idea to flash before installing Windows. Years ago on some random board I had, doing one of the BIOS upgrades made Windows go nuts because some of the ACPI tables changed and Windows decided that half the detected devices weren't there anymore and needed to redetect them.