Have in mind that both mainboards would not hold too well future upgrades, as they only have 2 SATA ports. Other thing that worries me is those ATX connectors, you'll have to do some cable management to avoid PSU cables getting in the way with the CPU heatsink. Hmmm, tricky. The ASRock is worse in that regard, but feature-wise seems better. VIA chipsets used to be OK back in the Pentium III times, now the poor guys got a little behind, but so did SiS, also a decent manufacturer. RAM, even if you put 4 GB, you won't use it (unless you plan to run Photoshop & Crysis side by side
)
EDIT: Of course I saw something wrong with the ECS, it uses the MicroATX form factor, that explains the two RAM sockets, although, funny enough, it says that supports 16 GB. Hmmm, finding two 8 GB DIMMs will be difficult and EXPENSIVE
. Besides, the ECS uses AC'97 for sound, while the ASRock uses HDA and the top-of-the-line Realtek chip as well.