When browsing a host, I found about a dozen interesting files, so I started downloading them.
I noticed in the Download-screen that for each file, Phex was trying to aquire a download-slot from the specific host, effectively hammering the host with requests even though it was returning busy (e.g. allowed only one download-slot).

I think that Phex should me more gentle when there are multi downloads from a single IP (which does not have to mean a single host, but in most cases it does). Not sure about how such behavior is treated on Gnutella, but on other network, you get banned by hosts for it.