Many ECS are fine, but first hand experience with MSI says "no contest" for me. My MSI K7T Turbo (plain) - my first build- and Turbo2 have been flawless with Duron and XP CPUs. Just compare forum threads to confirm which is the most stable, tho you'll fine FAR fewer re MSI due to far less complaints. I realize that ECS sold a terrific number of cheap K7S5As compared to MSI or about anyone, so that weighs in their favor on the number of complaints. But the number and seriousness turned me off, and the number of repeat customers ECS can garner remains to be seen.
An important comparison for me has to do with makers support. User after user said they couldn't get adequate support from ECS, and that they only cared about their big OEM cutomers. On the contrary, MSI replaced a 1.5 yr old MB for me with a newer model with no aggravation. They also sponser a good forum. Obviously, I'm a happy MSI user.