What's interesting about your 750ms is that it meets the requirement I saw at a FOSDEM talk that the boot time needed for an auto computer was 800ms, so that users could see blinky lights in less than one second. You're showing very impressive performance here for an x86.
You've also raised the bar again for proprietary bios -- they've been pretty boastful lately of hitting the 5 second or so mark, and you're showing we're still way faster. Plus, most of the time, we've found the proprietary BIOS vendors are being very creative in their timing claims :-)
Really great work!
ron