I have 2 different brand usb drives that I use, they transfer from USB to my PC in just a few minutes but a 30min video clip from the DVR to the USB drive takes close to 30 minutes. I don't think the DVR supports USB 2.0.
MY primary use for transfering video is to review the video. The dvr says its fast forwarding at 16x but it's nowhere near that speed in reality.
I don't think I can log into my dvr and transfer videos over the network, that would be even better if I could. The dvr is sitting between my computer and the router. I'm able to access the video feeds through my phone, I'll have to see if I can transfer data over the network as well.