Summary: With a price tag of around $300 US, the Intel DX79SI isn't a cheap board with cheaper X79 offerings coming in from as low as $219.99 US. There's nothing wrong with the DX79SI, but there's nothing that really makes it stand out that much, especially when you compare it to companies like ASUS, GIGABYTE, MSI and ASRock who offer us a really wide range of boards at different price points.
Conclusion: Considering that this board is significantly cheaper than the other two initial X79 boards we saw, it may well be good enough if you're certain of your storage needs now and down the line—and they aren't "Extreme." Just know what you're getting, and what you're not, before dropping coin.
Pros: Very easy interface for overclocking, Supports both SLI and CrossFireX, Accepts up to 64GB of RAM
Cons: No eSATA ports, Only two internal SATA 6Gbps ports, Text-based BIOS