I am aware of the PC4000 Ballistix being really good overclockers for 1GB modules, but I am also aware of the high number of those modules that have subsequently died even trying to run stock timings at DDR500 after a period of time
You still can't even begin to compare UCCC chips to the TCCDs and you really can't even touch the price difference...undisputably fact that 512MB will overclock better just like 256MB will overclock even better