3D Game Man posted a review on the Crucial DDR2 PC2-5300 ECC Memory

ECC memory is not something most will purchase since the majority of consumer motherboards don't require it. Fact is, most will purchase Non-ECC memory for its lower price and overclocking potential. ECC memory is in a category all its own, and is really the only choice though when building a reliable server. Servers typically process tremendous amounts of data in RAM. Therefore, this memory has to be error free, something non-ECC memory can't do. Errors in memory on mission critical servers could cause the entire computer to lockup..

Crucial DDR2 PC2-5300 ECC Memory Review