If I run backup with no -limit-rate argument, my backup runs at a very steady 14-15 Mbps (I can see this in the dashboard for my NAS). If I run it with -limit-rate 1024, it runs … well … around 1 kbps. I guess it seems self-evident why this is, obviously it’s interpreting the argument to -limit-rate as bits per second. But the documentation says this is in kilobytes per second.
-limit-rate the maximum upload rate (in kilobytes/sec)
So my upload is going ~8000 times slower than it should be.
I guess this is a documentation bug.