I work for Infinio - a leading provider of high performance I/O through a RAM-centric server-side cache.
We work with customers every day who are looking for high performance, (performance they just can't get any other way) and a few things come up repeatedly:
1. It's all about workload: The customers who care most about microsecond latency (i.e. going 20X faster than all-flash storage) rely on data processing jobs whose value to the business increases as their time to completion decreases: by hours, minutes, and seconds. Validating or dismissing a technology outside the context of workload is largely irrelevant.
2. For the times when a DRAM-only cache can't deliver the necessary performance (because of working set size), there's a huge benefit to having Optane over 3D NAND as the tier after DRAM.
3. It's not always about relative cost. For customers whose business results can be impacted by these technologies, absolute cost is a far more relevant metric. When you look at the impact of data reduction technologies (which are, admittedly, relevant across all media types), the difference in cost from an absolute perspective is often dwarfed by the overall ROI from the business results.
You can see our more complete POV blog post here: http://bit.ly/2u2yLcO