I was reading about the practical everyday usefulness of SSD speeds today. People always hype the sequential read. However its the small numbers of random reads and writes than actually matter for most useage. Sequential is only really for back-ups, file copies and so on. And for those, you'll need both disks to run the same speed - ie, if you do a file copy from disk to disk, the copy will go the speed of the slowest disk.
For example, to take advantage of an NVME internal disk copy, you'd need a USB 3.1 raid dual msata usb stick. Not exactly an every day scenario.
So in practice the NVME thing won't make much difference, nor will sata3. Its the random read-write speeds (small numbers of such), that's the number to pay attention to.
Was a really interesting little bit of research because it shows really, how for the most part, these broad bandswidths and high benchmarks are useless. The numbers to watch for performance are the random ones, without many iterations. Outside of that, only specialised applications will see any benefit, and only if there is no bottleneck in between.
For this of course, usually larger disks are fractionally higher. But I am not sure it would make any meaningful difference, if those random read/writes ("4K" in crystal mark), are fairly similar.