60+ connections to really see the bandwidth use I'm talking about.

I've observed some really annoying nodes (non-full nodes) that connect and just terrorize my bandwidth. I'm trying to recall the version string of one such node but I can't off the top of my head. At one point I started banning individual IPs based on the type of node they were running and I saw a drastic improvement, but this ended up being too much work.

I've seen things like 6 nodes with the same IP and different ports connected to my node.

The usage isn't constant. It comes in huge spikes that last for hours (up to days) at a time. Then there will be several hours with much less bandwidth used.

I don't know if node age has anything to do with how much the network will use it, but I've been running mine for many years now with near 100% uptime.