Stability mostly... from your accounts and reviews the Epox seems to be much more stable than the Asus. In additon, I can't verify the Epox board supports the xp 3000.

If bought 2 sticks of the Corsair 256MB, can I get the same performance/stability as a matched pair of something else? Do I "have" to get matched pairs? There is matched pairs of corsair 512mb sticks (1GB) but I don't want to pay that much for memory.