For the time being, and mainly because it took so long for SSD vendors to optimize Flash memory firmware, we are buying ONLY Samsung and SanDisk SSDs with a 10-year factory warranty:
just compute (retail price) / (warranty years) so as to "amortize" that capital investment.
Then, when the RocketRAID 3840A (or comparable NVMe RAID controller) stabilizes, we will be able to build our next workstation with any compatible PCIe 3.0 motherboard.
Our 13GB ramdisk is almost full, so we need a new workstation with at least 32GB of DRAM. But, we've been waiting because only a few PCIe 3.0 motherboards support 2 x U.2 ports (e.g. ASUS Hero Alpha), and we have a preference for RAID-0 arrays with 4 x member SSDs.
Also, if you know where to look, the Z170 motherboards with 2 x M.2 or 3 x M.3 slots situate those slots DOWNSTREAM of the DMI 3.0 link, and that DMI 3.0 link has the exact same UPSTREAM bandwidth as a single M.2 NVMe SSD! All of the benchmarks we have read all report the same ceiling ~3,500 MB/s
(i.e. 4,000 MAX HEADROOM minus aggregate controller overhead).
(The exact calculation for MAX is 32 Gbps / 8.125 bits per byte = 3,938.46 because the PCIe 3.0 standard uses the 128b/130b jumbo frame: 130 bits / 16 bytes per frame = 8.125 bits per byte .)
Lastly, something that readers here already appreciate, it took FOREVER for storage vendors to catch up with the bandwidth available to SLI and Crossfire setups i.e. HBAs with x16 edge connectors.
There is an engineering "elegance" that comes with x16 PCIe 3.0 lanes
and four x4 devices being fed with a full x16 edge connector:
4 @ x4 = x16
Highpoint appears to be one of the FIRST to satisfy most of the key requirements stated in this WANT AD:
http://supremelaw.org/systems/nvme/want.ad.htm
So, we wait: the wait will be worth it, imho.