I finally got sick of the Netgear USB Wifi adaptor we bought a couple of years back. It worked okay for a while, then we moved the desktop up front and it would repeatedly fall off the network under high-PPS or high-throughput situations, and the only way to get it to work was to unplug it and plug it back in.
I theorized that we could run an ethernet cable up the wall, along the top of the arch (there are gaps it can be tucked to make sure it stays put), and down to the desktop in the living room, and the only place it would be really noticable would be next to the sliding door, where it would be almost completely hidden by the vertical blinds. So I set out to the local Cheap as Chips, who have a 15m ethernet cable (far too long, but whatever) for very little money - though I can't remember what it actually cost.
The result? I finally got around to backing up the sole copy of our Mercedes Benz diagnostic VM off my laptop, at nearly 12MB/s for almost two hours without it dropping. Excellent. But why so slow? My first immediate thought was it was just a shitty disk - the drive we're using for data storage is the one I dug out of the USB enclosure it came in, which ended up dying. It's a "green" piece of shit, 5400RPM or something terrible with equally terrible cache and performance.
But I'm told that even a drive like that from a laptop should be more than capable of 30MB/s writes, so obviously something was amiss. I'm just not entirely sure I care enough to determine why it's not going as fast as it should. My AC1200 wireless card is capable of far more (and indeed I had no packet loss while it was copying, so obviously my LAN connection isn't the bottleneck) but I haven't looked any further.