hey,
CIFNet ... nice to hear that well known name here on the forum
i haven't got any personal experience with them, but they hosted an IRC Server on IRCnet (
www.ircnet.info 
) for about 4 years if i do remember it correctly ... they finally delinked 2000 because of heavy DoS attacks ... but their network is pretty stable. (so if you need filtering against attacks, i'm sure they have plenty of knowledge meanwhile

)
And it's a well known company, they've been around for years ...
and hey, they're nice people as they provided bandwidth to a non-commercial service.
just my 0,02$.
greets