Brian, why would you use WD Blacks in R0 with their TLER problem?
Also, some fellow video editors have had problems with WD Blacks due to its firmware and spinning down, which caused issues when editing video due to the drives spinning down all the time.
For the size of projects, if you can afford RE4's than I would rather use 2 600GB V-Raptors. But for a limited budget, I would use Samsung F3's as they have the highest throughput.
Furthermore, I think a major problem can arise from just using 2 drives in Raid 0. Aren't there times when you use more than one layer of video, which means you need a minimum of 250 MB/s read for 8bit and 300-330MB/s for 10bit. Thus, you would need at least 3 drives and nothing smaller than 1TB drives because each drive's throughput decreases as it fills up. I think the Samsung F3 1TB begins at 150MB/s and ends around 70MB/s.
Btw, do you use uncompressed AVI, Cineon or DPX and what software do you use? I use Premiere Pro and After Effects CS5, and I find DPX to work much better/smoother than AVI, especially in AE. I became aware of compositing with DPX when I first started using Nuke, and the reasoning is that the software does not need to decode any frames before or after the currently viewed frame unlike AVI. And at least in my experience, DPX does appear to be smoother especially when scrubbing.