i tested it on my home connection once & after a new block, it'd saturate the upstream for a good 30s or so. i guess that'd be a good way to slow down propagation, having 500+ connections and then limit upstream to 512Kbps or so.
not really, since I have 1000 max connections. it doesn't use epoll, so it crashes once you hit 1024 or so.
i've never gone above 800, w/ 500 outgoing
if i didn't set it for 500 outgoing connections, i'd max out at around 300. since i have sufficient bandwidth to handle 800 connections, it's then better to open 500 outgoing ones