Bill, sweet system, I am jealous, but the only thing I do not like is the Samsung EVO SSD's. One for the boot/applications is probably ok since you do not write much in normal use, but the EVO's have lousy real write rates from my testing. I have not tested the M.2 EVO's but the standard SATA III were so lousy I returned them and got the PRO's instead.
Do you really need the 1 TB hard drive? Go SSD all the way if you can. Seriously consider the M.2 Samsung SM951, it has phenomenal performance see this forum post of mine for the fantastic read and write performance, many times synthetic benchmarks are unbelievable, but with our Premiere Pro BenchMark (PPBM) disk intensive test I can write from a Premiere timeline at 1500 MB/second! Just do not waste it on the boot drive see if they can put the OS on the other SSD
Then for Premiere I have found that it is quite practical to have your project and media all on a plug-in Samsung T1 USB 3.0 flash drive, pull it out and instantly run on your studio computer.
From all of your in-depth responses on the forums, I have developed great respect for your opinions so I will follow your advice. Fortunately, this laptop will accomodate two SSD's and two traditional hard drives and is user upgradeable so I have considerable flexibility.
I am also interested in your opinion on the following tradeoff. I could stay in my price range with the Sager NP9778-S which upgrades the CPU to a Skylake i7-600K (4.0Ghz-4.2GHz, 8MB Intel Smart Cache) from the 2.66 GHz-3.5GHz version in the NP8678-S if I scale back the GPU from the NVIDIA GEForce GTX 980M (8.0G) GDDR5 PCI-E DX11 (Maxwell) to the GTX 970M (6.0G). I know that a more powerful GPU offloads processing demands from the CPU, but the practical application of this tradeoff is difficult for me to project. Since most of my editing will be performed on the studio computer and the laptop is also used for business applications, I am thinking the more powerful processor would provide me with more performance for the price. Can you help me to understand the relationship or advise as to what I may be overlooking?
For general information, on my studio computer I currently use a 1 TB Samsung 850 EVO as the system drive and a 1 TB Samsung 840 EVO with RAPID mode as my scratch disk. Using CrystalDiskMark 5.0.2 x64, I am getting sequential reads of 460 MB/s and sequential writes of 453 MB/s with the 850 EVO and sequential reads of 3327 MB/s and sequential writes of 1822 MB/s with the 840 EVO with RAPID mode because it is using system memory (of which I have 48 GB) as cache. I think this is what you refer to in your post as synthetic benchmarks, but my use experience has improved dramatically from using a Western Digital 4TB Black as the scratch disk. As you point out, hard drives are not in the same ballpark as SSD's for random read/write performance.
Again, I thank you for your willingness to share your vast technical knowledge with the rest of us who are just trying to maximize the performance of our systems.
I do like the trade-off of more CPU for less GPU. Premiere is very CPU intensive.
What you may want to do is download the PPBM and use it to measure the real write rate to your storage devices. If you do not want to repeatedly run the whole test I can email you a file which would allow you to just run the disk intensive test and determine the write transfer rate