It's the rich man's extreme edition. 16 cores that can turbo over 3 GHz, and the ability to easily have 96 GB of RAM (12*8GB for the SR-X)
Unnecessary? Yes.
Awesome for some? Yes.
Some of us could really use 16 core/32 thread monsters like this as a workstation for day-to-day work. Strong discrete graphics, and the resources to virtualize AND still have a full workload is nice. (The Asus Z9PE-D8 would be another choice).
I bought my X8DTH-6F over 2 years ago now. Sure, it can only turbo to 2.53GHz, but it had 8 cores / 16 threads and 6 channels of DDR3 in a land of 4-core Extreme Editions. It has integrated graphics, but it also has 7 PCIe x16 slots. I can easily virtualize 10 environments and still have RAM and processing power to run anything in my workflow. There are uses for these monsters, but it's not for most. But I think the price makes that obvious.