Just flashed mine,
Got message ‘image type ia32 is not supported by this x64 shell’ and then flashing stopped. Command line, typed ‘exit’. Tablet went through boot screen few times and in the end windows loaded. Had to change memory freq also. Was 1600 before flash and 1066 after. CPUID shows new BIOS and frequency now is ok too. Will update how battery is doing now. Mine was going down to 21% then it would stay at 21% for about an hour at low usage and suddenly die. Will see if that helps.
Regards,
Martin
UPDATE: Another success story with this update!