RE: Cogent input

I'm aware of some (regular?) depeering issues. The NANOG archives have

AFAIR, there has never been a black-holing, just disappearance of routes. If you are properly multihomed, this is irrelevant and you continue to eat your ice cream and chuckle while they fight it out. It's amusing, really.

I also know that their bandwidth is extremely cheap. This of course creates an issue for technical folks when trying to justify other upstream options that cost significantly more but also don't have a damaging history of getting depeered.

It's not as relatively cheap as it used to be. A variety of others can be had in the same ballpark (Telia, Tiscali, Seabone, etc.)