I finally took the plunge of flashing the Skyn3t BIOS for my MSI Twin Frozr edition, as the chip was clearly being held back by the power and voltage limitations. Increased my stable overclock from ~1163MHz (which dropped further under max load as it bumped against the power limit) to a rock solid 1241MHz with no problems. Going to try and push it a little further, but it's a nice gain anyway.
Did nothing for the crappy Elpida memory though, sadly. It will do 6200MHz and that's it. Anything above that results in a disastrous loss of performance, presumably through error checking kicking in.