My experience with a QNAP NAS is that large batch files transferred from an external hard drive through USB interface will move an order of magnitude faster with the USB-attached hard drive direct-connected to the NAS, rather than connected to a Windows computer and onward through Ethernet to the NAS.
However, smaller files, such as a single rip of a CD or SACD file on a Windows PC, transfer quickly and reliably from PC to a NAS via wireless or wired Ethernet.
However, smaller files, such as a single rip of a CD or SACD file on a Windows PC, transfer quickly and reliably from PC to a NAS via wireless or wired Ethernet.