NVMe is just a protocal designed just for SSDs that use PCI Express lanes and not the normal SATA Connectors (Which is AHCI)
So when it say it supports NVMe SSDs that just means you can get SSDs like the Samsung 960 and get super fast read and write speeds vs a normal SATA (They do make Samsung 850 M.2 SSDs which are SATA as the M.2 slot supports BOTH SATA and NVMe SSD's just one uses PCIe and one uses SATA)
now will you see a difference on every day stuff using NVMe vs a normal SATA SSD (Regardless if it is a 2.5 inch drive or a SATA M.2 SSD) the answer is no you will not. Unless you are doing a lot of work with things like RAW footage, a server running a 10Gbps Nic card that is being maxed out by file request, or SQL databases you...