Totally useless. The latency of pc <-> switch <-> NAS vs pc <-> NAS is really negligible.Yeah, I'm ultimately thinking straight connection between the computer and the NAS, so if the port on the computer and the port on the NAS support higher speeds, they ought to negotiate to their highest common speed. (no switch in between; the switch would be between the NAS and the rest of the network, as this is the single link that I'm most concerned about latency/speed. I can live with a few more switched between the PC and the internet.)
Unless both PC and NAS have 10gbps and your switch is 1 gbps only, this is useless.
I vote for QNAP/Synology which are very reliable boxes. Yeah, you will pay a price premium for both brands, especially with Thunderbolt 3 connectivity, but it totally worth it.