This is a path to DoS on the target server. Armed with a fat link, one Pulp server could put a major dent in the resources of an upstream server. Get three or four Pulp servers syncing on the same schedule, and you could cause major trouble without realizing it. Speaking from a systems perspective, I think this number should be a single digit, maybe around 4 or 5. Beyond that, any performance improvement will be relatively small, but the possibility of being "rude" to the upstream server goes up quickly.